Attempt to fix the bug
isMemberOf function
Using new helper function in group view
Refactoring isMemberOf to return group and user
Code cleanup on promises and error
Adding error promises and semicolons
Must be user to add to group as well
Fixing callbacks in isMemberOf
Yoni's comments
Merge pull request #53 from thelac/allen/issue_11

(Fixes #11) Preventing users not in a group from seeing or adding to a group