Install ryu's requirements

Install packages ryu requires explicitly becuase they are
no longer covered by neutron's requirements.
(They used to be until very recently.)

Closes-Bug: #1323136
Change-Id: I6a603d95c053ac1deba59d8e479dbaf1a70293f3
PKIZ is the default token provider

Keystone changed the default token provider to PKIZ from PKI.

Change-Id: I56b975383ded450308a8fe01908b6e5549e7cd74
Use correct path when extracting tar.gz image

Fix issue with file:/ image urls.

Change-Id: I8c5f5b27b5d6ebe5be84dc58d37752adbd12f89b
Closes-Bug: 1277609
Remove external attribute from the Provider Network

Co-Authored-By: Sridhar Gaddam <sridhar.gaddam@enovance.com>

Related-Bug: #1284718
Change-Id: Iad2f051a2b7b0a324dff4e716b8d2469a4f20895
Merge "Remove external attribute from the Provider Network"
Merge "Use correct path when extracting tar.gz image"
Merge "Install ryu's requirements"
Merge "PKIZ is the default token provider"
Merge branch 'master' of github.com:openstack-dev/devstack