Build a graphframes package and publish it to PyPi #491

I started setting up a setup.pyfile to build a proper package for GraphFrames to address an exception about missing graphframes.examples module in the unit test fixes I’m doing, porting node to pytest. I want to finish this work and build a proper package. It is strange this was never done! Note that the package name GraphFrames isn’t under our control and points at 0.6. graphframes-latest installs 0.8.3 though. I’ll pick something new.

@rxin @mateiz some context about why a package was never built would be helpful :) I don’t want to break anything…