Merge pull request #42 from javiercejudo/release-1.2.3

Release 1.2.3
Adds S3 to the README and removes {Track:js}. Stops hotlinking of MIT licence image.

Closes #43
Increases depth of shallow clone to prevent having to unshallow
Removes unshallow step for now
Brings back unshallow
Adds simple web process to run app locally with foreman
Change Procfile web process and update dependencies
Removes mason gem
Moves rev-manifest so that it isn't included in the appcache manifest
Updates dependencies and README
Bring Sauce Labs back and minor cleanup
Add tunnel identifier and add firefox to the tests
Remove firefox as it consistently timed out
Adds Sauce Labs badge
Specify browser to send coverage info
Load source files to fix code coverage
Send coverage stats from Chrome results
Reduce costly tests that are redundant
Run tests on all supported browsers

... and see if Sauce Labs doesn't timeout or something
Updates dependencies and introduces new SL browsers