Update the URL to the upper-constraints file to point to the redirect
rule on releases.openstack.org so that anyone working on this branch
will switch to the correct upper-constraints list automatically when
the requirements repository branches.

Until the requirements repository has as stable/zed branch, tests will
continue to use the upper-constraints list on master.

Change-Id: I2eec574d61d1514240654d81634a6a5d758b2432

Change-Id: I01c24c171a1d501e701a4b5fab69798d8c9f2e5f

The reason as following:
Create zed branch for client and non-client libs
https://review.opendev.org/c/openstack/releases/+/855929

DNM: dummy change to test gate health
https: //review.opendev.org/c/openstack/python-saharaclient/+/855787/1
Change-Id: I1e803725855fdbb7107a1f1a85acfe345c1103a0

Python 2 has been deprecated. This patch removes all
traces of six, unicode strings and Python 2 tweaks.

Change-Id: I74696d02558e0fa93ea1775057db13b4f72aed02

Six package is not used anymore

Change-Id: Ie72645229f23692d6bf87e58dd8ef212dd91189c

In zed cycle, OpenStack projects and oslo lib
has dropped the py3.6 and py3.7 support

- https://governance.openstack.org/tc/reference/runtimes/zed.html

I also decrepated oslo-log < 5.0.0, so we should bump oslo.log>=5.0.0.

Because of oslo.log>=5.0.0 depends on oslo.i18n>=3.20.0 as below, so we
also need to upgrade oslo.i18n.

The conflict is caused by:
    The user requested oslo.i18n>=3.15.3
    python-saharaclient 1.4.0 depends on oslo.i18n>=3.15.3
    castellan 0.16.0 depends on oslo.i18n>=3.15.3
    keystonemiddleware 4.17.0 depends on oslo.i18n!=3.15.2 and >=2.1.0
    oslo-config 6.8.0 depends on oslo.i18n>=3.15.3
    oslo-concurrency 3.26.0 depends on oslo.i18n>=3.15.3
    oslo-db 6.0.0 depends on oslo.i18n>=3.15.3
    oslo-log 5.0.0 depends on oslo.i18n>=3.20.0
    The user requested (constraint) oslo-i18n==3.15.3

The conflict is caused by:
    The user requested pbr!=2.1.0 and >=2.0.0
    bashate 0.5.1 depends on pbr>=1.6
    fixtures 3.0.0 depends on pbr>=0.11
    stestr 1.0.0 depends on pbr!=2.1.0 and >=2.0.0
    testresources 2.0.0 depends on pbr>=1.8
    testtools 2.4.0 depends on pbr>=0.11
    python-saharaclient 1.4.0 depends on pbr!=2.1.0 and >=2.0.0
    castellan 0.16.0 depends on pbr!=2.1.0 and >=2.0.0
    keystoneauth1 3.4.0 depends on pbr!=2.1.0 and >=2.0.0
    keystonemiddleware 4.17.0 depends on pbr!=2.1.0 and >=2.0.0
    oslo-concurrency 3.26.0 depends on pbr!=2.1.0 and >=2.0.0
    oslo-context 2.22.0 depends on pbr!=2.1.0 and >=2.0.0
    oslo-db 6.0.0 depends on pbr!=2.1.0 and >=2.0.0
    oslo-i18n 3.20.0 depends on pbr!=2.1.0 and >=2.0.0
    oslo-log 5.0.0 depends on pbr>=3.1.1
    The user requested (constraint) pbr==2.0.0

The conflict is caused by:
    The user requested oslo.serialization!=2.19.1 and >=2.18.0
    python-saharaclient 1.4.0 depends on oslo.serialization!=2.19.1 and >=2.18.0
    keystonemiddleware 4.17.0 depends on oslo.serialization!=2.19.1 and >=1.10.0
    oslo-log 5.0.0 depends on oslo.serialization>=2.25.0
    The user requested (constraint) oslo-serialization==2.18.0

Change-Id: Iebd0c795dcdd72dac1141cfe18d2dad5201147c1