Updating Bootstrap files to version 2.2.2, which will hopefully address #256.
Added Greg's instructions for contributing a blog post to CONTRIBUTING.md
Merge pull request #256 from jiffyclub/update-bootstrap-2.2.2

Drop down menu on SWC website not behaving as expected on mobile browsers
Merge pull request #260 from pipitone/contributing-blogging

Added Greg's instructions for contributing a blog post to CONTRIBUTING.md
Merge branch 'master' of github.com:swcarpentry/website
Fixing boot camp description