Promote more complete support for ISO 8601 time.
Promote more complete support for ISO 8601 time.

Support for ISO 861 time representation is now duplicated in nova:

  https://github.com/openstack/nova/commit/c30193fbf

and in glance:

  https://github.com/openstack/glance/commit/f8f9f171

Note this patch introduces a new dependency on python-iso8601, which
has already been packaged for Fedora, EPEL and Ubuntu/Debian.

Change-Id: I87c32effa97d3b7a8d869522b62c0c6fb31bcef8

klmitch/pbr,citrix-openstack-build/pbr,WiFast/pbr,citrix-openstack-build/pbr,varunarya10/pbr,klmitch/pbr,JioCloud/pbr,JioCloud/pbr,emonty/oslo-packaging,openstack-dev/pbr,citrix-openstack-build/pbr,WiFast/pbr,varunarya10/pbr,redhat-openstack/pbr,openstack-dev/pbr,emonty/oslo-packaging,redhat-openstack/pbr,openstack-dev/pbr