CSS specificity - use classes, not ids

[GaryJones]

Instead of giving your wrapping div an id attribute, give it a class attribute (just tgmpa is sufficient, no need for -form suffix). This way, the specificity scores for the CSS selectors will be considerably lower (20/21 instead of 110/111).

Same goes for removing tgmpa-go as an ID attribute value too.

[thomasgriffin]

Old, bad habits. You are helping me get rid of them. :) Will change this on dev and push to master.