Use template for lower-constraints

Small cleanups:

* Use openstack-lower-constraints-jobs template, remove individual
  jobs.
* Sort list of templates

Also, raise some lower-constraints since oslo.policy and
python-glanceclient requires a newer version.

Change-Id: I0304207ba4b8acc6a53da1f547b806bac8a917e6
Needed-By: https://review.openstack.org/623229

.zuul.yaml

@@ -1,15 +1,14 @@
 - project:
     templates:
       - check-requirements
+      - openstack-lower-constraints-jobs
       - openstack-python-jobs
       - openstack-python35-jobs
       - openstack-python36-jobs
       - publish-openstack-docs-pti
     check:
       jobs:
-        - openstack-tox-lower-constraints
         - horizon-openstack-tox-python3-django111
     gate:
       jobs:
-        - openstack-tox-lower-constraints
         - horizon-openstack-tox-python3-django111

lower-constraints.txt

@@ -25,7 +25,7 @@ Jinja2==2.10
 jmespath==0.9.3
 jsonpatch==1.21
 jsonpointer==2.0
-keystoneauth1==3.4.0
+keystoneauth1==3.6.2
 linecache2==1.0.0
 MarkupSafe==1.0
 mccabe==0.2.1
@@ -42,7 +42,7 @@ os-client-config==1.29.0
 os-service-types==1.2.0
 osc-lib==1.10.0
 oslo.config==5.2.0
-oslo.context==2.20.0
+oslo.context==2.22.0
 oslo.i18n==3.20.0
 oslo.log==3.36.0
 oslo.serialization==2.25.0