drop an unused import from the testing code

This extra import brings in src/main, which then brings in more
dependencies on JavaScript libraries.  To build the tests within
Google it's easier to just not have these dependencies, given
that this import isn't used anyway.

Author: evmar

test/test_support.ts

@@ -15,7 +15,6 @@ import * as ts from 'typescript';
 
 import * as cliSupport from '../src/cli_support';
 import * as es5processor from '../src/es5processor';
-import {toClosureJS} from '../src/main';
 import {BasicSourceMapConsumer, sourceMapTextToConsumer} from '../src/source_map_utils';
 import * as tsickle from '../src/tsickle';