Use tempest.lib code in tempest

Now that tempest_lib code is copied back into tempest, stop using
tempest_lib in tempest, and start using the copied code.

Remove the dependency to tempest_lib from requirements, and drop
the script to use tempest_lib in tempest. Add os-testr to the
test-requirements.

Partially implements bp tempest-lib-reintegration

Change-Id: I21ab5fe6349f72c98ac9f960a29bf62e813f8b1b
diff --git a/tempest/scenario/manager.py b/tempest/scenario/manager.py
index a996ffe..eb29176 100644
--- a/tempest/scenario/manager.py
+++ b/tempest/scenario/manager.py
@@ -20,8 +20,6 @@
 from oslo_log import log
 from oslo_serialization import jsonutils as json
 import six
-from tempest_lib.common.utils import misc as misc_utils
-from tempest_lib import exceptions as lib_exc
 
 from tempest.common import compute
 from tempest.common.utils import data_utils
@@ -29,6 +27,8 @@
 from tempest.common import waiters
 from tempest import config
 from tempest import exceptions
+from tempest.lib.common.utils import misc as misc_utils
+from tempest.lib import exceptions as lib_exc
 from tempest.services.network import resources as net_resources
 import tempest.test