Calculate digito_agencia internally and removed of santander bank according to new documentation.
Calculate digito_conta_corrente and digito_codigo_cedente internally.
Change validation of carteira to verify inclusion in carteiras_suportadas.
Revised carteira and valor_documento validations.
Rename Santander doc file.
valor_formatado_para_codigo_de_barras was not properly formatting the cents.
Merge pull request #4 from eltonlk/master

Adding internal calculations and validation of wallet altered