Added missing curl needed in health checks

docker/Dockerfile

@@ -83,7 +83,7 @@ WORKDIR /opt/fiware-pep-steelskin
 RUN \
 	# Ensure that Git is installed prior to running npm install
 	apt-get update && \
-	apt-get install -y git && \
+	apt-get install -y git curl && \
 	echo "INFO: npm install --production..." && \
 	npm install --production && \
 	# Remove Git and clean apt cache