Icon for ReplicaSets missing from v1.1.18

[Dennis Zhang]

The icon for replicaset is not found in the image it appears. The for the icon at path img/res/rs-grey.svg is returning a 404:

I did a sanity check in the repo for this file in the repo and it doesn't appear to be there on master branch either.

[Ben Coleman]

Thanks for spotting.

Fixed in PR #46 and release 0.1.19