Require Docker V17.06.1 or greater to build

Makefile

@@ -190,10 +190,9 @@ define docker-build-mq
 	  --volume "$(realpath ./downloads/)":/usr/share/nginx/html:ro \
 	  --detach \
 	  nginx:alpine
-	# Make sure we have the latest base image
-	$(DOCKER) pull $(BASE_IMAGE)
-	# Build the new image
+	# Build the new image (use --pull to make sure we have the latest base image)
 	$(DOCKER) build \
+	  --pull \
 	  --tag $1 \
 	  --file $2 \
 	  --network build \

docs/building.md

@@ -2,7 +2,7 @@
 
 ## Prerequisites
 You need to ensure you have the following tools installed:
-* [Docker](https://www.docker.com/) V17.05 or later
+* [Docker](https://www.docker.com/) V17.06.1 or later
 * [GNU make](https://www.gnu.org/software/make/)
 
 ## Building a production image