Including entity Range Snapshot to Kalibro gem
Improving tests for Range Snapshot
Implemented repository observer entity
Rake task for tests
Including base tool entity to kalibro gem
Finished tests for repository observres entity

Moreover, changed the content of fixture to a fictional user; and fixed grammatical errors on repository test.
Included Metric Configuration Snapshot to Kalibro gem
Added the entity DateModuleResult

Two unit tests are pending because the depend on ModuleResult.