Update CONTRIBUTING.md

.github/CONTRIBUTING.md

@@ -12,9 +12,4 @@ Note that redis shouldn't be running - the build will start instances as needed.
 
 ## Running the tests
 
-``` bash
+Requires Docker in a running state.
-export REDIS_BIN=<path to redis binaries>
-
-# And finally running the build
-mvn -DargLine="-Xmx2g -DredisBinary=$REDIS_BIN/redis-server" -Punit-test clean test -e
-```