Feed version dropdown is overlapped by a map button

[evansiroky]

Observed behavior (please include a screenshot if possible)

A button on the feed source map overlaps a dropdown. See screenshot:

Expected behavior

Dropdown should overlap map button.

Steps to reproduce the problem

Go to a feed with lots of versions and click the version dropdown.

Any special notes on configuration used

Observed on NYSDOT production website.

Version of datatools-ui and datatools-server if applicable (exact commit hash or branch name)

datatools-ui: https://github.com/conveyal/datatools-ui/commit/8580318856b9123ecea32276e3bcf8c7e03b2f49 datatools-server: https://github.com/conveyal/datatools-server/commit/566e4da3242f1c79b0e509e358bc639752d0d254