Use my recently-created PHP port of the VGNG.

This replaces a python dependency, git submodule (and the necessary
init), and a squeamish exec call with a simple composer dependency with
a nicer interface.

This project also has the potential to open up other random name
generators - not just the video game generator.
Merge pull request #9 from nubs/random-name-generator

Use my recently-created PHP port of the VGNG.