Add accessibility Identifier  to the options button to be able to tap on it using KIF.
Merge pull request #329 from wordpress-mobile/feature/AccessibilityIdentifierOnOptions

Add accessibility Identifier  to the options button to be able to tap on...
Merge branch 'release/0.2.3' of github.com:wordpress-mobile/WordPress-iOS-Editor into issue/171-post-divider

# By Sérgio Estêvão
# Via Diego Rey Mendez (1) and Sérgio Estêvão (1)
* 'release/0.2.3' of github.com:wordpress-mobile/WordPress-iOS-Editor:
  Add accessibility Identifier  to the options button to be able to tap on it using KIF.