Update python-manilaclient and horizon required

We need a newer version of the SDK to enable
features supported by newer API versions. While
this commit doesn't enable new features, future
commits will; so bumping up the required SDK
version is a necessary predecessor. Using 2.7.0
gives us access to API versions upto 2.63.
Version 2.7.0 was released in June 2021. [1][2]

Horizon 18.3.1 is off of the stable/ussuri release
of horizon, shipped in Apr 2020 [3]

[1] https://lists.openstack.org/pipermail/release-announce/2021-June/011255.html
[2] https://docs.openstack.org/releasenotes/python-manilaclient/xena.html#relnotes-2-7-0-stable-xena
[3] https://review.opendev.org/c/openstack/releases/+/721047
Change-Id: I100a1ec20a0c59c0a7023136e0eab7a0b63b6709
Signed-off-by: Goutham Pacha Ravi <gouthampravi@gmail.com>

lower-constraints.txt

@@ -75,7 +75,7 @@ python-cinderclient==5.0.0
 python-dateutil==2.7.0
 python-glanceclient==2.9.1
 python-keystoneclient==4.1.1
-python-manilaclient==1.29.0
+python-manilaclient==2.7.0
 python-mimeparse==1.6.0
 python-neutronclient==6.7.0
 python-novaclient==10.1.0

releasenotes/notes/python-manilaclient-yoga-ef2c44b205fa216b.yaml

@@ -0,0 +1,5 @@
+---
+upgrade:
+  - |
+    This version of manila-ui requires `python-manilaclient >= 2.7.0
+    <https://docs.openstack.org/releasenotes/python-manilaclient/xena.html#relnotes-2-7-0-stable-xena>`_

requirements.txt

@@ -8,6 +8,6 @@ django-compressor>=2.0 # MIT
 iso8601>=0.1.12 # MIT
 oslo.utils>=4.7.0 # Apache-2.0
 python-keystoneclient>=4.1.1 # Apache-2.0
-python-manilaclient>=1.29.0 # Apache-2.0
+python-manilaclient>=2.7.0 # Apache-2.0
 
-horizon>=17.1.0  # Apache-2.0
+horizon>=18.3.1  # Apache-2.0