Improve script bin/integration-tests.sh

bin/integration-tests.sh

@@ -1,13 +1,20 @@
 #!/bin/bash
+# if you want to run integration tests against a different version of MongoDB
+# export the MONGO_VERSION variable.
+# For example: export MONGO_VERSION=3.4 && ./bin/integration-tests.sh
+if [[ -z $MONGO_VERSION ]]; then
+    MONGO_VERSION=3.6
+fi
+
 cd "$(dirname ${BASH_SOURCE[0]})"/.. || exit 1
 
-echo "### Starting mongodb container..."
-docker run --rm --name it-mongo -d -p 27017:27017 mongo:3.6
+echo "### Running volatile mongo:$MONGO_VERSION Docker container..."
+CONTAINER_ID=$( docker run --rm -d -p 27017:27017 mongo:"$MONGO_VERSION" )
 
 echo "### Build RESTHeart and run integration tests..."
 mvn clean verify -DskipITs=false
 
-echo "### Cleaning up..."
-docker stop it-mongo
+echo "### Cleaning up mongo:$MONGO_VERSION container..."
+docker stop "$CONTAINER_ID"
 
 echo "### Done."