Align filters via CSS (#90)

While reviewing #90 @tojonmz suggested in his commit https://github.com/tojonmz/mozmill-dashboard/commit/3801fcd2742461a9ec0554dd78c537198e1e5920 I should get credit for the CSS solution.

I don't really care about credit, but since I'll be unavailable for a few days, I should get this up.

cc @whimboo this fixes #90 with only CSS so we don't open the lions den to change markup (which will require JS changes as well due to tight coupling)

Also this is visible at: http://mozmill-sandbox.blargon7.com/