Fix .info_columns not aligning properly and awkward padding on .buttons

Firefox wasn't displaying `.button`s and `.info_column`s properly because it uses different `box-sizing`. Including a one line Bourbon mixin for both fixed the problem.

I also changed the width of the `.info_column`s to `percentage(1/3)`, which is super cool. That way they each take up 1/3 of the row.