Fix "variable does not exists" issue

See #5

Fix hostname slow issues

PR #4

First release version

Compiled file can be found here

What's included in this first release ?

• a build command (+ docs)
• a release command
• a deploy command combining build and release commands.
• a basic rollback command (+ docs)
• a delete command
• customisation at pretty much every steps with a hook mechanism (docs)