contrib/docker/centos6

--- a/contrib/docker/centos6	Mon Jul 24 20:39:26 2017 -0400
+++ b/contrib/docker/centos6	Thu Jul 27 14:15:26 2017 +0200
@@ -7,3 +7,5 @@
 RUN yum install -y tar
 # For creating repo meta data
 RUN yum install -y createrepo
+# For python
+RUN yum install -y readline-devel openssl-devel ncurses-devel zlib-devel bzip2-devel