Enable Ruby 1.9.3 on Travis

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Simple captcha for signup page
Add mobile signup page captcha. Add test for user.sign_up method. Rewrite simple_captcha views to haml. Revert .rvmrc, fix indentation in config examp$
Merge pull request #4659 from jaywink/simple-captca-for-signup-page

Simple captca for signup page
Add drawer menu to mobile version

  - Added basic drawer menu with JS code working on /stream
add drawer to mobile

  - Functional drawer with menu icon
Add new icons to the mobile version
Fix mobile publisher
Remove margin of the nav elem
Compose_mobile icon
Make the drawer scrollable
Add aspects list and mentions link
Fix tests
Add link on aspects and allow to show / hide them in the drawer
Add current user avatar in the drawer