switch to oslo.utils

oslo.utils is released and corresponding code in oslo-incubator has
been removed.

Change-Id: Ic3a13380809a8b00c979e5ac405b4084f486a31d
sync oslo code

- sync code up to Change-Id: Ie6064e73abe4b0729498a0343d50e1be35684b75
- includes fix to resolve alarm-evaluator failure
- does not include openstack/common/strutils sync as it requires
  test update

Co-Authored-By: Vaibhav Kale <vaibhav_kale@persistent.co.in>
Closes-Bug: #1357343
Change-Id: Ieec08520cb39c5bf2e795dfeb3e36e52c6fd2a82
Remove runtime dependency on python-pbr