Add CEP valition

[LucasAndrad]

Add CEP validation
Maybe I could use this API to check if the CEP exists:
https://viacep.com.br/

Actually a good idea is to use 3 or more API to search for a CEP, this one sounds good two
https://postmon.com.br/

This one is good, doesn't need any token
http://apps.widenet.com.br/busca-cep/api/cep/72110040.json

This one is really fast but I need to inform my token to use the API
http://cepaberto.com

I can also crawler this Correio web page
http://www.buscacep.correios.com.br/sistemas/buscacep/

font:
This post on br stackoverflow has a lot of links:
https://pt.stackoverflow.com/questions/400/como-buscar-um-endere%C3%A7o-por-cep-nos-correios

• Connect to API - postmon
• Connect to API - widenet
• Connect to API - via_cep
• Treat Errors
• Validation
• Call
• Test (Rspec)