[Bug] The close button in InfoWindow is invisible

[sflahave]

Description

The close button on the InfoWindow is not visible. You can see this on the current demo page: https://visgl.github.io/react-google-maps/examples/markers-and-infowindows

Steps to Reproduce

Create a marker with an InfoWindow. Or just visit the demo page https://visgl.github.io/react-google-maps/examples/markers-and-infowindows

Environment

• Library version: latest
• Google maps version: weekly
• Browser and Version:
• OS:

Logs