Update and rename the script for testing with docker

Author: Lee Miller

docker-test.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+DOCKERFILE=.buildbot/tox-bionic/Dockerfile
+
+docker build -t pybm/tox -f $DOCKERFILE .
+
+if [ $? -gt 0 ]; then
+    docker build --no-cache -t pybm/tox -f $DOCKERFILE .
+fi
+
+docker run --rm -it pybm/tox