Update .jshintrc
Update .jshintrc

grunt aborts due to delete being a reserved word.

Per https://github.com/gruntjs/grunt/issues/752, updating .jshintrc so that es5 is used for linting.
cjbarth/grunt-assets-versioning,theasta/grunt-assets-versioning,theasta/grunt-assets-versioning,cjbarth/grunt-assets-versioning