Make sure docker container is created before starting it

Author: Pierstoval

Makefile

@@ -16,7 +16,7 @@ help: ## Show this help.
 install: vendor imagemagick-docker ## Install composer dependencies and Docker image for testing
 .PHONY: install
 
-start: ## Start Docker image for testing
+start: imagemagick-docker ## Start Docker image for testing
 	@docker start $(IMAGEMAGICK_DOCKER_IMAGE)
 .PHONY: start
 
@@ -47,4 +47,4 @@ imagemagick-docker:
 		dpokidov/imagemagick:latest \
 		sleep 9999999 \
 		>/dev/null
-.PHONY: imagemagick-docker
+.PHONY: imagemagick-docker