Add bootstrap classes to ReST admonitions
Add draft release announcement for Flycheck
Make topic titles stand out
Finalize the release announcement for Flycheck 0.15
Merge branch 'flycheck-0.15-release' into source

* flycheck-0.15-release:
  Finalize the release announcement for Flycheck 0.15
  Make topic titles stand out
  Add draft release announcement for Flycheck
  Add bootstrap classes to ReST admonitions