Beta is now called Alpha.
Removed alpha/beta words from the opt-in mechanism, as these seem to change too often
Remove unused beta switch
Replace beta class with alpha
Revert "Remove unused beta switch"

This reverts commit a9804008b9b681596d023e346ff004b5da95f705.
WIP alpha message & a means to flash it at users
jshint
Merge branch 'master' of github.com:guardian/frontend into alpha
Move release message to it's own template & apply basic style
Slightly better wording
Merge pull request #1573 from guardian/alpha

Alpha