Google-Maps-Rails (gmaps4rails) does not display markers when upgrading to 0.10.0

When upgrading the gmaps4rails gem to version 0.10.0 the markers are not displayed any more on the map.

There is an issue raised about the bug here.
To make the markers appear downgrade to version 0.9.1 of the gem.

update: or upgrade to 0.10.2 as the bug is fixed.