Replace git.openstack.org URLs with opendev.org URLs

1. Thorough replacement of git.openstack.org URLs with their
opendev.org counterparts.
2. dict_object.keys() is not required for *in* operator

Change-Id: Ie1d0c828522ae92b01f28e7017fd7fd42c2e91e7

README.rst

@@ -7,9 +7,9 @@ Team and repository tags
 
 .. Change things from this point on
 
-=================
- oslo.concurrency
-=================
+================
+oslo.concurrency
+================
 
 .. image:: https://img.shields.io/pypi/v/oslo.concurrency.svg
     :target: https://pypi.org/project/oslo.concurrency/
@@ -21,6 +21,6 @@ external processes.
 
 * Free software: Apache license
 * Documentation: https://docs.openstack.org/oslo.concurrency/latest/
-* Source: https://git.openstack.org/cgit/openstack/oslo.concurrency
+* Source: https://opendev.org/openstack/oslo.concurrency
 * Bugs: https://bugs.launchpad.net/oslo.concurrency
 * Release Notes: https://docs.openstack.org/releasenotes/oslo.concurrency/

oslo_concurrency/processutils.py

@@ -174,7 +174,7 @@ class ProcessLimits(object):
     }
 
     def __init__(self, **kw):
-        for limit in self._LIMITS.keys():
+        for limit in self._LIMITS:
             setattr(self, limit, kw.pop(limit, None))
 
         if kw:
@@ -184,7 +184,7 @@ class ProcessLimits(object):
     def prlimit_args(self):
         """Create a list of arguments for the prlimit command line."""
         args = []
-        for limit in self._LIMITS.keys():
+        for limit in self._LIMITS:
             val = getattr(self, limit)
             if val is not None:
                 args.append("%s=%s" % (self._LIMITS[limit], val))

tox.ini

@@ -5,7 +5,7 @@ envlist = py35,py27,pep8
 [testenv]
 install_command = pip install {opts} {packages}
 deps =
-  -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
+  -c{env:UPPER_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/branch/master/upper-constraints.txt}
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
 # We want to support both vanilla stdlib and eventlet monkey patched