Add deployment SHA to Heroku Build version

Adding the SHA to the build "version" allows things like checking what's
currently not deployed, or checking if a branch is currently "locking"
our app.
Merge pull request #41 from ResultadosDigitais/add-version-to-build

Add deployment SHA to Heroku Build version
try to get some docs going
minor fixups
try fixing up table rendering
make tables work
fixups
fixups
restructure notifiers some
a bit more
Merge pull request #42 from ZeroFucks/try-out-docs

Try to get some docs going
use resque-lock
break event handling out into their own jobs/queues
lock deployments on an environmental basis
debug
these are queueing instead of blocking up
Merge pull request #43 from ZeroFucks/lock-deployments-to-repo-envs

Only allow one deployment of an app per environment at a time
use the right queue name
try resque-lock-timeout for desired behavior
check if deployments are locked