Share specs for override and default
Refactored EnvironmentObject delete_<precedence>_attribute to follow pattern set by other methods in the class. Also DRY'd up the tests and added type checking to the unset method.
Follow precedent of indented private methods
Use Hashie::Mash instead of VariaModel::Attributes
Merge pull request #248 from RiotGames/unset_environment_attribute

Unset environment attribute