Fix missing bdist_wheel

Found this trick at https://github.com/numpy/numpy/blob/master/setup.py

Importing setuptools make numpy's version of setup find the
'bdist_wheel' command. It is now possible to deploy wheel files with

    python setup.py bdist_wheel upload

Signed-off-by: Jonas Kalderstam <jonas@kalderstam.se>
Merge pull request #64 from spacecowboy/bdist_fix

Fix missing bdist_wheel