Updated gitignore
Rewrite amberbit config for easier tests [work-in-progress]
Changed structure of AmberbitConfig module.

Extracted key object - Config. It gets two paths, to the
default options and custom/private options.

Also moved creation of deep hash struct, to the hash struct object.
Added additional specs and fixtures to check edge cases
Check hash keys for conflicts

Raise errors on no options, instead of returning a nil - which is a
default behaviour for OpenStruct.
Added HashStruct#to_hash
Render ERB from config files, i.e. helpful on heroku
Get rid of Rails dependency

Add rails engine, only if working within rails. Use lighter rspec, etc.
Also improved initializer, so it's loaded now even before environment
configurations.
Run rake tasks only once, and update gitignore file
Split module into separate files
Updated readme and changelog