chore(Dockerfile): update deis/base to v0.3.6

Author: Matthew Fisher

Dockerfile

@@ -1,4 +1,4 @@
-FROM quay.io/deis/base:v0.3.5
+FROM quay.io/deis/base:v0.3.6
 
 ENV LANG=en_US.utf8 \
     PG_MAJOR=9.4 \
@@ -49,7 +49,7 @@ RUN buildDeps='gcc git libffi-dev libssl-dev python3-dev python3-pip python3-whe
     apt-get clean -y && \
     # package up license files if any by appending to existing tar
     COPYRIGHT_TAR='/usr/share/copyrights.tar' && \
-    gunzip $COPYRIGHT_TAR.gz && \
+    gunzip -f $COPYRIGHT_TAR.gz && \
     tar -rf $COPYRIGHT_TAR /usr/share/doc/*/copyright && \
     gzip $COPYRIGHT_TAR && \
     rm -rf \