Cleanups and improvements

* Update readme
* Add non-cores to graph
Improve node detection

* Track emails
* Prefer author email over commiter email addresses
* compare emails in all lowercase
* If cannot detect company, print email domain
* display company name/domain on second line for readability
Use OpenStack CookieCutter

Make this repo into a proper python project.

Add tox interface.

* Add py27 job (with stub test)
* Add doc job
* Add pep8 job