Se agregan los modelos UML en VisualParadigm
Merge pull request #1 from gianfrancob/master

Singleton
Actualizo ".gitignore" para ignorar archivos .db (WindoR)
Merge remote-tracking branch 'upstream/master'
implementacion vanesa
Merge pull request #2 from crisgutierrez/master

implementacion vanesa
Merge remote-tracking branch 'upstream/master'