Added testing for grading settings

Please note that 2 tests will not reliably work:
Deleting a grade- Was able to circumvent this with javascript
Moving the grade slider- Could not circumvent, is skipped but the framework is in place
Added in the drag and drop support
Merge branch 'master' into jonahstanley/add-gradingsettings-tests
Fixed click to comply to new css_click
Merge pull request #115 from edx/jonahstanley/add-gradingsettings-tests

Added testing for grading settings