Adding travis v2

* adding Travis
* using `rake` to run the tests. 
* improving `.gitignore`
* deleting `Gemfile.lock`
* cleaning `Gemfile`
* dropping Spork and Guard


PD: I use `rake db:setup` on Travis because we are using a *clone* from Rankia DB but there is no migrations for that.
PD2: The best commit is 16eb75d because now we can use `RSpec` 2.14 or whatever