Add support for Compute Engine #34

Compute Engine: https://developers.google.com/compute/docs/reference/latest/
Python Compute Engine: https://developers.google.com/compute/docs/api/python-guide
Boto EC2: https://github.com/boto/boto/tree/develop/boto/ec2
Boto EC2 tutorial: https://boto.readthedocs.org/en/latest/ec2_tut.html
Boto EC2 API docs: https://boto.readthedocs.org/en/latest/ref/ec2.html