Rescue Addressable::IDNA exceptions

[dentarg]

From https://github.com/sporkmonger/addressable/blob/addressable-2.5.0/lib/addressable/idna/pure.rb#L378-L383

• PunycodeBadInput
• PunycodeBigOutput
• PunycodeOverflow

I think all these cases was previously covered by twingly-url rescueing IDN::Idna::IdnaError, which was removed in 057f675 when we dropped use of libidn.

[dentarg]

The reason why the others isn't being rescued is that we want to write specs when adding them, thus we need input that triggers them (so we are able to prevent regressions in the future). :)