Added ReportPresenter
Added reporting methods for Clock model
Added support for reports endpoint

* New reports resource
* New xls formatter added
* Simplified presenters
* Added 'erubis' gem for xls generation
Added better seeds
Implemented monthly report
Added missing tests for Presenter::Employee methods
Merge branch 'master' into reports-endpoint-implementation

Conflicts:
	Gemfile.lock
	config/application.rb
Regenerated Gemfile.lock
Merge pull request #5 from AxionTecnologia/reports-endpoint-implementation

Reports endpoint implementation