Switch from fedora-26 to fedora-27 testing

Now that we have fedora-27 images online, start testing against that.

It also seems that pip3 will use /usr/local so we can remove override
from systemd for fedora.

  https://fedoraproject.org/wiki/Changes/Making_sudo_pip_safe

Change-Id: I21f5c2b5cefd3b8b08478de5db9a3104f1610b5a
Depends-On: https://review.openstack.org/543013/
Depends-On: https://review.openstack.org/543019/
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

.zuul.yaml

@@ -8,9 +8,9 @@
       - zuul: openstack/ansible-role-zuul
 
 - job:
-    name: ansible-role-zuul-fedora-26
+    name: ansible-role-zuul-fedora-27
     parent: ansible-role-zuul
-    nodeset: fedora-26
+    nodeset: fedora-27
 
 - job:
     name: ansible-role-zuul-ubuntu-xenial
@@ -19,15 +19,15 @@
 
 - project:
     templates:
-      - windmill-jobs-fedora-26
+      - windmill-jobs-fedora-27
       - windmill-jobs-xenial
     check:
       jobs:
-        - ansible-role-zuul-fedora-26
+        - ansible-role-zuul-fedora-27
         - ansible-role-zuul-ubuntu-xenial
         - tox-linters
     gate:
       jobs:
-        - ansible-role-zuul-fedora-26
+        - ansible-role-zuul-fedora-27
         - ansible-role-zuul-ubuntu-xenial
         - tox-linters

templates/etc/systemd/system/zuul-executor.service.d/centos-7.conf

@@ -1,5 +1,3 @@
 # This file is generated by Ansible
 #  DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
 #
-[Service]
-Environment="PREFIX=/usr"

templates/etc/systemd/system/zuul-merger.service.d/centos-7.conf

@@ -1,5 +1,3 @@
 # This file is generated by Ansible
 #  DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
 #
-[Service]
-Environment="PREFIX=/usr"

templates/etc/systemd/system/zuul-scheduler.service.d/centos-7.conf

@@ -1,5 +1,3 @@
 # This file is generated by Ansible
 #  DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
 #
-[Service]
-Environment="PREFIX=/usr"

tests/templates/etc/systemd/system/override.conf.j2

@@ -2,8 +2,5 @@
 #  DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
 #
 [Service]
-{% if ansible_os_family == 'RedHat' %}
-Environment="PREFIX=/usr"
-{% endif %}
 Group={{ zuul_user_group }}
 User={{ zuul_user_name }}