Issue66

Found only a bug in the main where centLensx/y must be an array instead of a list. When this was solved the mainWFS.py worked without any errors. Also included a test function and made some adjustments to the mainWFS.py regarding the number of samples the intensity distribution has.
Can you give me:
- Your version of numpy
- Your version of scipy
- Your version of Python
- Your OS

And undo those kind of changes in the main loop before making a pull request.