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

Thorough replacement of git.openstack.org URLs with their opendev.org
counterparts.

Change-Id: I83a2db1878b71707752dcd04d7bfb37e884604c0

README.rst

@@ -23,7 +23,7 @@ How to use with devstack:
 
 Add the following to your devstack ``local.conf`` file::
 
-    enable_plugin sahara-dashboard https://git.openstack.org/openstack/sahara-dashboard
+    enable_plugin sahara-dashboard https://opendev.org/openstack/sahara-dashboard
 
 
 To run unit tests:
@@ -40,7 +40,7 @@ outside of the horizon codebase, in the repository.
 Links:
 ------
 
-Sahara project: https://git.openstack.org/cgit/openstack/sahara
+Sahara project: https://opendev.org/openstack/sahara
 
 Sahara at wiki.openstack.org: https://wiki.openstack.org/wiki/Sahara
 

tox.ini

@@ -6,7 +6,7 @@ skipsdist = True
 [testenv]
 usedevelop = True
 install_command = pip install {opts} {packages}
-deps = -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
+deps = -c{env:UPPER_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/branch/master/upper-constraints.txt}
        -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 whitelist_externals = /bin/bash
@@ -59,7 +59,7 @@ commands = {envpython} {toxinidir}/manage.py test --settings=sahara_dashboard.te
 
 [testenv:releasenotes]
 basepython = python3
-deps = -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
+deps = -c{env:UPPER_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/branch/master/upper-constraints.txt}
        -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html