Tidy up Workboard CSS a little
Summary:
- Custom scrollbars, colors
- New div with some better padding (floor for the column)
- More consistent spacing around the board itself.
- Slightly darker columns
- Smaller horizonal scrollbar
Test Plan:
Chrome Mac / Desktop.
{F1100342}
Reviewers: epriestley
Reviewed By: epriestley
Subscribers: Korvin
Differential Revision: https://secure.phabricator.com/D15217