fix file ownership (#5)

Author: Ahmad Iqbal Ali

Dockerfile

@@ -1,11 +1,12 @@
 FROM alpine:3.6
 
-COPY init.sh /
 RUN apk add --update git openssh
 
 RUN addgroup -g 1000 -S git && \
     adduser -u 1000 -S git -G git
 
+ADD [--chown=git] init.sh /
+
 RUN mkdir /home/git/.ssh/  && \
     chown git /home/git/.ssh && \
 	mkdir /repository && \