Added support to not send responses when the handler has already called finish()

[vivekfantain]

I found a bug that caused Tornado to fail because we are sending message after calling finished(). I had submitted an earlier patch that didn't pass tests. This version should. Hopefully!

[hfaran]

Hmm, not sure if the test failures here are related to your change; maybe a breaking change in jsonschema. I'll take a look.

[hfaran]

@vivekfantain I just pushed #111 which pins some dependencies to fix the failing tests. Can you merge from the latest upstream master? That should fix it.

[vivekfantain]

Now I have a new issue

platform darwin -- Python 2.7.15, pytest-3.10.1, py-1.8.0, pluggy-0.9.0 -- /Users/vivekv/projects/Tornado-JSON/.tox/py27-tornado3/bin/python
cachedir: .pytest_cache
rootdir: /Users/vivekv/projects/Tornado-JSON, inifile:
plugins: cov-2.6.0
collected 28 items                                                                                                                                                                                               

tests/func_test.py::APIFunctionalTest::test_asynchronous_handler PASSED                                                                                                                                    [  3%]
tests/func_test.py::APIFunctionalTest::test_db_conn PASSED                                                                                                                                                 [  7%]
tests/func_test.py::APIFunctionalTest::test_empty_resource PASSED                                                                                                                                          [ 10%]
tests/func_test.py::APIFunctionalTest::test_post_custom_validator_class PASSED                                                                                                                             [ 14%]
tests/func_test.py::APIFunctionalTest::test_post_request PASSED                                                                                                                                            [ 17%]
tests/func_test.py::APIFunctionalTest::test_post_schema_with_default_but_use_defaults_false PASSED                                                                                                         [ 21%]
tests/func_test.py::APIFunctionalTest::test_post_use_defaults PASSED                                                                                                                                       [ 25%]
tests/func_test.py::APIFunctionalTest::test_post_use_defaults_no_need_of_default PASSED                                                                                                                    [ 28%]
tests/func_test.py::APIFunctionalTest::test_synchronous_handler PASSED                                                                                                                                     [ 32%]
tests/func_test.py::APIFunctionalTest::test_url_pattern_route PASSED                                                                                                                                       [ 35%]
tests/func_test.py::APIFunctionalTest::test_view_db_conn PASSED                                                                                                                                            [ 39%]
tests/func_test.py::APIFunctionalTest::test_write_error PASSED                                                                                                                                             [ 42%]
tests/test_api_doc_gen.py::test__get_tuple_from_route PASSED                                                                                                                                               [ 46%]
tests/test_api_doc_gen.py::test__get_api_docs PASSED                                                                                                                                                       [ 50%]
tests/test_api_doc_gen.py::test___get_notes PASSED                                                                                                                                                         [ 53%]
tests/test_schema.py::TestSchemaMethods::test_defaults_basic PASSED                                                                                                                                        [ 57%]
tests/test_schema.py::TestSchemaMethods::test_defaults_nested_object_default PASSED                                                                                                                        [ 60%]
tests/test_schema.py::TestSchemaMethods::test_defaults_no_defaults PASSED                                                                                                                                  [ 64%]
tests/test_schema.py::TestSchemaMethods::test_input_schema_clean PASSED                                                                                                                                    [ 67%]
tests/test_schema.py::TestSchemaMethods::test_input_schema_clean_ignore_other_types PASSED                                                                                                                 [ 71%]
tests/test_schema.py::TestSchemaMethods::test_input_schema_clean_no_defaults PASSED                                                                                                                        [ 75%]
tests/test_tornado_json.py::TestRoutes::test_get_routes PASSED                                                                                                                                             [ 78%]
tests/test_tornado_json.py::TestRoutes::test_gen_submodule_names PASSED                                                                                                                                    [ 82%]
tests/test_tornado_json.py::TestRoutes::test_get_module_routes PASSED                                                                                                                                      [ 85%]
tests/test_tornado_json.py::TestUtils::test_api_assert PASSED                                                                                                                                              [ 89%]
tests/test_tornado_json.py::TestJSendMixin::test_success FAILED                                                                                                                                            [ 92%]
tests/test_tornado_json.py::TestJSendMixin::test_fail FAILED                                                                                                                                               [ 96%]
tests/test_tornado_json.py::TestJSendMixin::test_error FAILED                                                                                                                                              [100%]

==================================================================================================== FAILURES ====================================================================================================
__________________________________________________________________________________________ TestJSendMixin.test_success ___________________________________________________________________________________________

self = <tests.test_tornado_json.TestJSendMixin object at 0x10217ea50>

    def test_success(self):
        """Tests JSendMixin.success"""
        data = "Huzzah!"
>       self.jsend_rh.success(data)
E       AttributeError: 'TestJSendMixin' object has no attribute 'jsend_rh'

tests/test_tornado_json.py:180: AttributeError
____________________________________________________________________________________________ TestJSendMixin.test_fail ____________________________________________________________________________________________