Dockerfile: only install openssh client, use apk --no-cache

Author: l-lotz

Dockerfile

@@ -4,9 +4,7 @@ LABEL maintainer Bill Wang <ozbillwang@gmail.com>
 
 COPY docker-entrypoint.sh /docker-entrypoint.sh
 
-RUN apk --update add git less openssh && \
-    rm -rf /var/lib/apt/lists/* && \
-    rm /var/cache/apk/*
+RUN apk --update --no-cache add git less openssh-client 
 
 VOLUME /git
 WORKDIR /git