Display import button only for admin

 - Check if the current  user can perform import action.
Handle incorrect JOSN file

 - Display warning if the import fails or an attempt is made import
invalid json file.
Spelling and UI Changes.

 - Make the name of exporting activity bold.

 - Change the spelling of import, export button.
Authorize if the user can perform export

 - authorize export activity for current user
Rspec tests for export functionality

 - Test cases for exporting an activity.