Removed testnumber file

You can set testnumber in test/jasmine/tests/domain_ref_test.js if you
want to run a single test.

Author: nicholas-esterer

test/jasmine/assets/domain_ref/testnumber.js

@@ -4,8 +4,8 @@ var domainRefComponents = require('../assets/domain_ref/components');
 var createGraphDiv = require('../assets/create_graph_div');
 var destroyGraphDiv = require('../assets/destroy_graph_div');
 var Plotly = require('../../../lib/index');
-// optionally specify a test number in a file to run just a single test
-var testNumber = require('../assets/domain_ref/testnumber');
+// optionally specify a test number to run just a single test
+var testNumber = undefined;
 
 function makeTests(component, filter) {
     return function() {