Validation of CPF is not 100% correct

Validation of CPF is not 100% correct - it allows invalid CPF's
A CPF like '094.050.986-59ABCDEF' is valid according to the code and should be invalid

I do not read & write portuguese - a friend who can, went through the issues and found that this issue and #121 are related - so this is actually a duplicate of #121 - I fixed it in pull request #151 ...

New to github. Closed as duplicate