adding search feature to users index page
Refactoring things according to the review on the pull request.
Removed the helper_method declaration (method was already deleted). Upgraded the user model tests to use the let! syntax and reduced the number of users in the test to just 3.
Removed the redundant css classes and added a line at the end of the file.
Removed an extra line from the search_bar partial and added an extra line to the user partial.
Merge pull request #180 from zendesk/fneves/add_search_to_users_page

adding search feature to users index page