Merge pull request #295 from karlcow/issue273-githubrequest

Better headers and better caching Fix #273
Revert "Better headers and better caching Fix #273"
Merge pull request #296 from webcompat/revert-295-issue273-githubrequest

Revert "Better headers and better caching Fix #273"
Improved "checkParams" method.
Merge remote-tracking branch 'origin/dev.webcompat.com'

* origin/dev.webcompat.com: (160 commits)
  Issue #313 - Don't add ratelimit headers manually.
  Comments for 429 error handler.
  Remove unused helper method (for now).
  Issue #313, #319: HTTP 429 error hander.
  Uh, whitespace commit.
  Issue #313 (+#319) - put a limit on searches from our side.
  Issue #313 - Add flask limiter to help with tracking rate limiting on our side.
  ISsue 313 - AJAX error handler to detect when search rate limit is hosed.
  Pep8 tweaks.
  Issue 313 - Add helper method to format github rate limit timestamps.
  Add component : Hero, issues # #316 #318
  Add FlashMessage state is-active, #315 #316
  Add component : FlashMessage, issues # #316 #315
  Move footer.css to components folder
  Add component : Footer, issue #315
  Issue #313 - expose rate limit headers to XHR
  Add component : Navbar, issue #315
  Use threequals to make jshint happy.
  Improve contrast ratio for a11y #305
  Flash message, covered the header entirely, issue #314
  ...
Update dev to staging in CONTRIBUTING.md.
Restore some of the code lost in merge.

I'm really confused by this... I must have screwed up the merge
conflicts. :(
Issue #322 - Fix contributing page tests.
Issue #322 - Fix index.js tests.