Merge with upstream
Add libxslt1-dev to stackato.yml
Remove threadsafe! from production config
Fix env var name for SECRET_TOKEN
Ruby 2.1.1 not yet supported, use 2.0.0
Threadsafe.rake no longer required
Add SECRET_TOKEN env var to stackato.yml
Add 'Deploying to Stackato' to README
Update handling of secret_key_base
Update README