Add database configuration files for mysql and postgres
Add travis configuration, and testing on multiple DBs

To achieve testing on multiple databases the Gemfile
contains db adapters for the specific platforms and
environments
Remove requires of ci_reporter gem
Travis builds only on 1.9.3 and in test env
Trace rake errors
Setup environment.local.rb on travis
Solve migrations error on travis
Retore testing full matrix on travis
Extend section about installing rubygems [ci skip]
Simplify and speed up build preparing scipts
Restore ci_reporter gem

* Require CI env variable to run simplecov
Restore db creation in before script on travis
Update SimpleCov condition in test/test_helper.rb
Use COVERAGE env variable to run SimpleCov

http://about.travis-ci.org/docs/user/ci-environment/#Environment-variables
Travis sets the CI env var to true so before this commit, the coverage was
computed on Travis
Add jruby condition in database.yml files
Add Procfile for foreman
Use application.yml instead of environment.local.rb on travis
[Gemfile] Moved rufus-scheduler out from :ruby group, and did a bundle update.
So that we can test-drive rufus-scheduler on JRuby in next commit.
Add ci:build rake task
Rewrite the lib/setup.rb script to a Thor task