Mention invoke==0.13.0 requirement in docs

Author: felliott

CONTRIBUTING.rst

@@ -45,7 +45,7 @@ Configure development environment and Install the development dependencies.
     $ pip install virtualenv
     $ pip install virtualenvwrapper
     $ mkvirtualenv --python=`which python3` mfr
-    $ pip install invoke==0.11.1
+    $ pip install invoke==0.13.0
 
 
 Lastly, install mfr in development mode. ::

README.md

@@ -41,7 +41,7 @@ pip install virtualenv
 pip install virtualenvwrapper
 mkvirtualenv --python=`which python3.5` mfr
 pip install setuptools==30.4.0
-pip install invoke==0.11.1
+pip install invoke==0.13.0
 invoke install
 invoke server
 ```
@@ -90,6 +90,8 @@ invoke test
 
 - The error `def create_default_context(purpose=ssl.Purpose.SERVER_AUTH, *, cafile=None, capath=None, cadata=None): SyntaxError: invalid syntax` can be fixed by restarting your virtual environment. The problem should not reoccur.
 
+- `invoke $command` results in `'$command' did not receive all required positional arguments!`: this error message occurs when trying to run MFR v0.19.0+ with `invoke<0.13.0`.  Run `pip install invoke==0.13.0`, then retry your command.
+
 ### Create your own module
 
 Interested in adding support for a new provider or file format? Check out the CONTRIBUTING.rst docs.

docs/install.rst

@@ -16,13 +16,13 @@ Or download one of the following:
 
 Make sure that you have installed pspp, are using python3.5, and have installed invoke for your current python3 version.
 
-Install the version of invoke found in the requirements.txt file. Currently 0.11.1
+Install the version of invoke found in the requirements.txt file. Currently 0.13.0
 
 Install ``invoke``:
 
 .. code-block:: bash
 
-    pip install invoke==0.11.1
+    pip install invoke==0.13.0
 
 Install requirements: