update docker README [ci skip] [circleci skip]

DOCKER/README.md

@@ -1,6 +1,7 @@
 # Supported tags and respective `Dockerfile` links
 
-- `0.9.0`, `0.9`, `latest` [(Dockerfile)](https://github.com/tendermint/tendermint/blob/d474baeeea6c22b289e7402449572f7c89ee21da/DOCKER/Dockerfile)
+- `0.9.1`, `0.9`, `latest` [(Dockerfile)](https://github.com/tendermint/tendermint/blob/809e0e8c5933604ba8b2d096803ada7c5ec4dfd3/DOCKER/Dockerfile)
+- `0.9.0` [(Dockerfile)](https://github.com/tendermint/tendermint/blob/d474baeeea6c22b289e7402449572f7c89ee21da/DOCKER/Dockerfile)
 - `0.8.0`, `0.8` [(Dockerfile)](https://github.com/tendermint/tendermint/blob/bf64dd21fdb193e54d8addaaaa2ecf7ac371de8c/DOCKER/Dockerfile)
 - `develop` [(Dockerfile)](https://github.com/tendermint/tendermint/blob/master/DOCKER/Dockerfile.develop)