Added version argument

Author: SloCompTech

hooks/build

@@ -12,4 +12,5 @@ docker build \
     --build-arg BUILD_DATE=`date -u +"%Y-%m-%dT%H:%M:%SZ"` \
     --build-arg VCS_REF=`git rev-parse --short HEAD` \
     --build-arg VCS_SRC="https://github.com/SloCompTech/docker-openvpn/commit/$SOURCE_COMMIT" \
+    --build-arg VERSION="$SOURCE_BRANCH" \
     -t $IMAGE_NAME .