add maintainer to sample Dockerfile.complex

Author: aptalca

Dockerfile.complex

@@ -1,5 +1,5 @@
 ## Buildstage ##
-FROM lsiobase/alpine:3.9 as buildstage
+FROM lsiobase/alpine:3.12 as buildstage
 
 RUN \
  echo "**** install packages ****" && \
@@ -17,5 +17,7 @@ COPY root/ /root-layer/
 ## Single layer deployed image ##
 FROM scratch
 
+LABEL maintainer="username"
+
 # Add files from buildstage
 COPY --from=buildstage /root-layer/ /