Continuous integration with travis

[beniz]

This is the continuous integration and automated compilation across multiple OS. This is already partially in place, and results are available at https://travis-ci.org/beniz/libcmaes/builds

This is only building on linux for now, but I will grow the set of platform, most especially to include OSX.

• platforms: linux and osx
• python bindings
• unit tests

[beniz]

Travis doesn't seem to take no more requests for multi-os builds, so OSX may have to wait... See http://docs.travis-ci.com/user/multi-os/
EDIT: hum, did write to them and was granted access, great!

[beniz]

Travis fails with gtest on Linux, with very weird behavior, where gtest is detected, but the system doesn't find rules in the makefile to compile the tests (whereas it correctly acquires the list of test files from the same makefile section). I'm bailing on this for now as Travis is too time-consuming to remotely debug with commited changes to the conf file. I believe this is not a big issue as well.