Prevent instantiation of abstract classes whose superclass isn't Object

Fixes #9
Merge branch 'master' of https://github.com/dkubb/abstract_type into fix-new-method-for-classes-without-object-as-their-superclass

Conflicts:
	spec/unit/abstract_type/abstract_method_declarations/included_spec.rb
Fix some code formatting offences in the metrics
Killed the mutants
Merge pull request #10 from misfo/fix-new-method-for-classes-without-object-as-their-superclass

Prevent instantiation of abstract classes whose superclass isn't Object