Update python-requests and python-urllib3
Update python-requests and python-urllib3

To match upper-constraints.

https://review.openstack.org/#/c/501669/ has fixed a bug
in puppet-nova that was blocking requests update.

Change-Id: Ib208860b9c0f33592cfdf1a6e9d9094c6d7928fe

redhat-openstack/rdoinfo,javierpena/rdoinfo