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

more info http://lists.openstack.org/pipermail/openstack-discuss/2019-May/006478.html

Change-Id: I100b31eb5ab57af244390f199f26340048d55375

CONTRIBUTING.rst

@@ -16,4 +16,4 @@ Pull requests submitted through GitHub will be ignored.
 
 Bugs should be filed on Launchpad, not GitHub:
 
-    https://bugs.launchpad.net/nova-powervm
+   https://bugs.launchpad.net/nova-powervm

tox.ini

@@ -20,11 +20,11 @@ setenv =
   OS_TEST_TIMEOUT=60
   PYTHONDONTWRITEBYTECODE=1
 deps =
-  -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
+  -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/test-requirements.txt
   -egit+https://git.openstack.org/openstack/nova#egg=nova
-  -rhttps://git.openstack.org/cgit/openstack/nova/plain/test-requirements.txt
+  -rhttps://opendev.org/openstack/nova/raw/branch/master/test-requirements.txt
 whitelist_externals =
   bash
 commands =
@@ -72,7 +72,7 @@ commands =
 
 [testenv:docs]
 deps =
-  -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
+  -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -W -b html doc/source doc/build/html
 
@@ -95,5 +95,5 @@ deps =
   -c{toxinidir}/lower-constraints.txt
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
-  -egit+https://git.openstack.org/openstack/nova#egg=nova
-  -rhttps://git.openstack.org/cgit/openstack/nova/plain/test-requirements.txt
+  -egit+https://opendev.org/openstack/nova#egg=nova
+  -rhttps://opendev.org/openstack/nova/raw/branch/master/test-requirements.txt