Pyeee

* Added tests for general functions, function and exe wrappers,
Morris Elementary Effects, SA test functions, screening, and tee
to increase coverage.
* Renamed ntsteps to nsteps in eee to be consistent with
screening/ee.
* Change check of logfile in eee: check for string rather than
file handle to be independent of Python version.
* Replaced kwarg.pop mechanism in exe wrappers because it removed
the keywords from subsequent function calls.

* Second release online on Github, simply to trigger zenodo.

* First release on zenodo.

* Replaced numpy.matrix arithmetic with numpy.dot on ndarray in.
Morris sampling: no numpy deprecation warnings anymore.

* Added test for see, using logfile and several processes in eee.
* Added seed keyword to screening/ee.
* Distinguish iterable and array_like parameter types in all
routines.
* Added verbose keyword to eee / see.
* Added Elementary Effects (ee) in README.md and Quick usage
guide.
* Corrected error in description of pyeee in setup.py, and set
development status to 4 - Beta.

* Initial release on PyPI.