Add support for verticalAlign

[calumbrodie]

The css property 'https://developer.mozilla.org/en-US/docs/Web/CSS/vertical-align' is currently unsupported

[zartdinov]

OMG! Where is verticalAlign?

[mshwery]

Should be fairly straightforward to add that! PRs welcome of course :)

Or, if not, we can try to get to it soon! // cc @colinlohner

[zartdinov]

OK, I will try ;)

[Rowno]

Looks like the verticalAlign property was released in v4.1.0.