Small corrections

pica-mattermost/Dockerfile

@@ -25,8 +25,8 @@ RUN apk add --no-cache \
 	&& rm -rf /tmp/*
 
 # Get Mattermost
-RUN mkdir -p /mattermost/data /mattermost/plugins /mattermost/client/plugins
-    curl https://releases.mattermost.com/$MM_VERSION/mattermost-team-$MM_VERSION-linux-amd64.tar.gz | tar -xvz
+RUN mkdir -p /mattermost/data /mattermost/plugins /mattermost/client/plugins \
+    && curl https://releases.mattermost.com/$MM_VERSION/mattermost-team-$MM_VERSION-linux-amd64.tar.gz | tar -xz \
     && cp /mattermost/config/config.json /config.json.save \
     && rm -rf /mattermost/config/config.json \
     && addgroup -g ${PGID} mattermost \