Add a method to set the deleteMethod
Call the delete method on each tracked object when deleteSaved is called
Facade methods for deleting and setting delete method
Add DeleteMethodNotFound exception
We need delete methods on FactoryMuffin Facade classes
We don't need to call create all of the time, we only need ::instance

Also add public delete methods until we fix #97 - This is because we
are calling ::create on the factory types instead of instance when
needed
Delete saved methods after tests finish
Exception improvements

The DeleteMethodNotFound now extends MethodNotFound.
All exceptions support optional message overriding.
Merge pull request #125 from GrahamCampbell/delete-exception

Exception Improvements
Fixed up the save exception
Docblock corrections
Ordered use statements
Merge pull request #128 from GrahamCampbell/delete-fixes

Delete Fixes
Merge pull request #124 from thephpleague/delete

Delete objects