Bug fix regarding readlink in git-flow context

Dockerfile

@@ -27,5 +27,7 @@ RUN echo "Install dorgflow" && \
     ./gitflow-installer.sh install stable && \
     rm gitflow-installer.sh && \
     \
+    sed -i -e "s/readlink -e/echo/g" /usr/local/bin/git-flow && \
+    \
     rm -rf /var/cache/* && \
     rm -rf /root/.composer/cache