Update zuul settings, drop Python 3.{6,7} support.

Change-Id: I38dd2866d436134bfe8f2370cc251d853481bced

.zuul.yaml

@@ -1,11 +1,12 @@
 - project:
+    queue: adjutant-ui
     templates:
       - build-openstack-docs-pti
       - check-requirements
       - horizon-non-primary-django-jobs
       - openstack-cover-jobs-horizon
       - openstack-lower-constraints-jobs-horizon
-      - openstack-python3-wallaby-jobs-horizon
+      - openstack-python3-jobs-horizon
     check:
       jobs:
         - openstack-tox-pep8

requirements.txt

@@ -7,6 +7,6 @@
 # be installed in a specific order.
 #
 # PBR should always appear first
-pbr>=2.0.0 # Apache-2.0
+pbr!=2.1.0,>=2.0.0 # Apache-2.0
 
-horizon>=14.0.0.0b3  # Apache-2.0
+horizon>=18.1.0  # Apache-2.0

setup.cfg

@@ -6,7 +6,7 @@ description-file =
 author = Adrian Turjak
 author-email = adriant@catalyst.net.nz
 home-page = https://github.com/catalyst/adjutant-ui
-python-requires = >=3.6
+python-requires = >=3.8
 classifier =
     Environment :: OpenStack
     Framework :: Django
@@ -18,9 +18,8 @@ classifier =
     Programming Language :: Python :: Implementation :: CPython
     Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.6
-    Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
+    Programming Language :: Python :: 3.9
 
 [files]
 packages =