Cannot scroll regions pane

[TassSinclair]

Scenario

Given I have entered my AWS CLI credentials
And the page populates with resources across 15 or more regions

Expected

When I scroll the "regions" panel on the left (holding my mouse cursor over, and scrolling)
Then the "regions" panel scrolls, showing regions that were previously off the end of the page
And I can select one of those regions

Actual

When I scroll the "regions" panel on the left (holding my mouse cursor over, and scrolling)
Then the "resources" panel scrolls instead
And I cannot pick any of the regions that are off the end of the page

Affects

Commit 650d3bb (currently head)

Tested on

• macOS 10.12.6, Firefox 57.0.4
• macOS 10.12.6, Chrome 63.0.3239