Add Makefile directives for pylint/pyflakes/pep8 code checks.

 * ADD .pylintrc to tweak pylint a bit; otherwise it warns about some rather
   ridiculous things.
It's not 2009 anymore…

(cherry picked from commit e2a7f9319310a3c23a0c110963071cb1f4592c76)
Add .travis.yml file.