Ironic: Continue pagination when listing nodes

Ironic API supports pagination and limit the number of items returned
by the API based on a config option, by default a max of 1000 items is
returned per request. The Ironic client library by default respect that
limit, so when the Nova Ironic driver list the nodes it might hit that
limit and the wrong information will be passed to nova.

This patch fix the problem by passing a "limit=0" flag to the client
library to tell it to continue pagination until there're no more nodes
ot be returned.

Change-Id: I63795e2b4de828fa41e97812e99a714f04d2f580
Closes-Bug: #1367349
Updated from global requirements

Change-Id: I11c99071cab59458a093485aa903b5fff9b8c1d5
Revert "Switch Nova to use oslo.concurrency"

This patch made unit tests stop running (always runs 0 unit tests) we
should revert and put a check in place to prevent that from happening
so that we don't regress the rest of Nova trying to figure out the
oslo.concurrency issue.

This reverts commit 382294762b08abb1921a77b00608ac941478ce05.

Change-Id: I98b04ac2a0ba67ba8af44867799317fdf95b8aff
error if we don't run any tests

This makes subunit-trace error out if it finds that there were no test
results in the subunit stream. This guards against the case where
something breaks the test toolchain and we stop running tests
entirely. Copied over from equivalent code in Tempest where this has
served us well.

Change-Id: I765395335a68dfc7eb754317f8c45c3dfdd85949
Merge "Ironic: Continue pagination when listing nodes"
Merge "Updated from global requirements"