Merge pull request facebook#3488 from delftswa2014/grunt-coverage-fix

Removed build:test from test:coverage.

Author: zpao

Gruntfile.js

@@ -201,7 +201,6 @@ module.exports = function(grunt) {
   ]);
 
   grunt.registerTask('test:coverage', [
-    'build:test',
     'build:withCodeCoverageLogging',
     'test:webdriver:phantomjs',
     'coverage:parse'