validaciones de datos de entrada
Merge pull request #1 from jelitox/master

merge
Merge branch 'master' of github.com:infoalex/sigerisa
Merge branch 'master' of https://github.com/infoalex/sigerisa
Merge branch 'master' of github.com:infoalex/sigerisa
Merge branch 'primer_aporte'
Merge branch 'master' of github.com:infoalex/sigerisa