Clarify env adapter keys and mappings parameters [ref #7]
Enhance env adapter parameters documentation [ref #7]
Merge branch 'feature/simplify_key_value_mappings_for_env_adapter' into develop
Move the key formatting in utils module
Add is_nested_key util
Support nested key getitem on adapters
Support nested setitem on adapters
Fix py3.3 compatibility with reduce function
Fix legacy merge fail content in README