Add target="" support for button component

[vincentducorps]

No description provided.

[rafibomb]

We have no issue adding this, other than added complexity.

Is there a reason we need it in an email though? And as far as I can tell, most webmail clients automatically open links in new tabs without there being a need for a specified target.

[vincentducorps]

This is particularly convenient for the web version of the email. :)

[gakimball]

Eventually the parser should copy all (non-custom) attributes from the original tag to the new one, for all components.

[rafibomb]

@vincentducorps I think we'll pull this in, but do you think all buttons should automatically have a target="_blank"? Perhaps we can extend Inky to add that?

[rafibomb]

Also - Just published the Foundation for Emails 2.1 release blog post and the release went out this morning! We also started a discussion on the future of Inky and what amazing integrations can be made. I'm sure you have some comments, questions, or ideas: http://foundation.zurb.com/forum/posts/39717-architecting-the-future-of-foundation-for-emails

[vincentducorps]

I don't know, it depends on your specifications.
I believe that we must allow the possibility to specify.

Maybe "_blank" by default and the possibility to make it in "_self".
Otherwise, the proposal @gakimball is not a bad idea.

[rafibomb]

Sorry that this might have gotten crossed up with some of the other PR's

I saw that #42 was merged and does the same thing and this one covers all attribute use cases: #45

Do you see anything missing on those that should be addressed?