Add curl package to CI build stage

.gitlab-ci.yml

@@ -18,7 +18,7 @@ build:
   image: "debian:stretch"
   script:
     - apt-get -q update
-    - env DEBIAN_FRONTEND=noninteractive apt-get -qy install make default-jre-headless wget unzip
+    - env DEBIAN_FRONTEND=noninteractive apt-get -qy install curl make default-jre-headless wget unzip
     - make
   artifacts:
     paths: