* Removes 'alternative_title' from terminology specified in HydraPbcore::Datastream::Document. Removes tests referring to 'alternative_title'.
* Changes 'summary' to 'description' in terminology specified in HydraPbcore::Datastream::Document.
* Removes individual descriptions in terminology specified in HydraPbcore::Datastream::Document. Replaced by accessors for 'description' and 'description.type'.
* Adds accessors for each specific type of title.
* Changes the default xml template to be extremely bare bones.
* Updates Gemfile.lock after bundle install.