Support formatMessage api

[baktun14]

Hi, thanks for putting this together!

I think it would be great to add formatMessage into the mix since it's basically the same as FormattedMessage.

[BANG88]

Did you mean parse formatMessage method ? I personally don't use this method, PR are welcome :)

[baktun14]

Yea that's what I meant, I will try to do this this week-end

[BANG88]

fixed by 1609c18