Padding bank & account #33

[michlikv]

I added zero padding to numeric fields when IBANs are being created. I am not sure about other fields - alphanumeric or alphabetical, but zero padding might come useful - regarding countries mentioned in the issue + CZ and SK.

The padding is in separate method in Builder (addLeftPadding()) and can be called at any point while building the IBAN. Unset fields are not created by this method, so incomplete IBANs stay invalid.

[coveralls]

Coverage decreased (-0.9%) to 98.152% when pulling c51641949b10d3d17d818a582bc164bdcb967142 on michlikv:PaddingBankAccount into ce1ca12b947755d1d96aab294d1ea15c78090ca2 on arturmkrtchyan:master.

[Dr4K4n]

:+1: great solution, doesn't break existing code, would very much like this to be merged.

[hajk1]

Duplicate issue #33