[Bug] it should not try to represent callable objects as a string
Merge pull request #194 from docteurklein/bugfix/invokable-object-represented-value

[Bug] it should not try to represent callable objects as a string
Remove unused unwrapper from Collaborator
Added support for array keys with no values
Merge pull request #208 from nixilla/master

HaveKey matcher should match even if given key has no value
Add exception factory
Add creation of property not found exception to factory
Remove unused imported exception namespace
Add subject exceptions to the factory
Add accessing non-existent property exception to factory
Remove unused imports from Caller spec
Add exception factory to caller construct (baby step)
Delegate method not found exception creation to factory from Caller
Remove argument 'message' from methodNotFound factory
Shorten argument list in exception factory
Spec Caller delegation of property not found to factory
Spec Caller delegation of method not found to factory
Spec Caller delegation of class not found to factory
Spec Caller delegation of calling method on non-object
Spec Caller delegation of setting property on non-object