First refactoring for including integration tests in the CI process. 

That's only a first step on the road since the integration tests need a lot of works however this PR include:
- a new travis.yml
- replacing all `LITHIUM_*` constants in flavour of `Libraries::get()` when possible;
- minor modifications on the test API. Now tests must be suffixed by `'Test'` (which was in a way the used convention);
- fix tests (mainly integration tests);
- typo fix;
- config is loaded on the fly during the CI process (config files are in ci/config).

I'm not an expert of "travis.yml" so advices are welcome.

Thats all folks!

Hehe click on the details link just below     ↓