Add the ability to specify the return value on BlankSlate methods
Minor change to simplify the methods that are iterated when creating the BlankSlate class.
1.1.0 used method_defined? which has an arity of 2 in Ruby 2.6 but 1 in previous rubies. This was changed to check instance_methods(false)
Make BlankSlate a shallow copy of a class. Ancestor methods are preserved.
Initial release