Fix typo
Remove initialize method and delegate it to Nestable
Check if the object is actually deserializable.

Hashie::Mash is not deserializable but it responds to :deserializable?
method.
Refactor list, show, and browse command.
Remove attr_accessors in Settings so that getters work properly
Refactor checkout, approve, merge, and close commands.
Refactor prepare and create commands.
Merge branch 'refactor_internals' into dummy_branch