Update .gitignore to exclude the keys/ testing directory, and *.log files.
Add Makefile for common testing tasks.
Add TravisCI config file for continuous integration testing.

 * The travis-lint tool reports that the YAML syntax is valid:
   ∃!isisⒶwintermute:~/code/riseup/python-gnupg ∴ travis-lint
   Hooray, /home/isis/code/riseup/python-gnupg/.travis.yml seems to be solid!