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.
Show the user the default values for the questions.  Fixes #12.
Add name/version so that --version works.
Merge pull request #15 from nubs/default-values

Show the user the default values for the questions.  Fixes #12.
Update composer to use herrera-io/version#7.