React Select is pinned at 1.0.0-rc.5

react-select recently released several new release candidates:

https://github.com/JedWatson/react-select/blob/master/HISTORY.md#v100-rc10--2017-09-13

In COMPASS-1217, in order to unblock CI and other tickets in Compass, this was pinned to the known good v1.0.0-rc.5 version.

Acceptance criteria:

• Fix issue by bumping to latest version of react-select, or creating an upstream issue and working with the author to resolve
• Propagate fix into document-validation plugin (and bump in Compass)
• Propagate fix into Compass (Indexes Tab, or plugin if it has been plugin-ified)