zuul: Use all rather than all-plugin for tox_envlist

Since 'all-plugin' is deprecated in Tempest, this is to
switch to 'all' instead in .zuul.yaml; for more info,
see: 9b4c50cf63/tox.ini (L64)

Depends-On: Ib3264f54075216471720483c8dd816887c1f413c
Change-Id: I440b6cff2b5378e18304017589e3e7cf4748c28c

.zuul.yaml

@@ -31,7 +31,8 @@
         neutron-trunk: true
       tempest_concurrency: 2
       tempest_test_regex: (?!.*\[.*\bslow\b.*\])(^patrole_tempest_plugin\.tests\.api)
-      tox_envlist: all-plugin
+      tox_envlist: all
+      tox_extra_args: --sitepackages
 
 - job:
     name: patrole-base-multinode
@@ -60,7 +61,8 @@
         neutron: true
       tempest_concurrency: 1
       tempest_test_regex: (?=.*\[.*\bslow\b.*\])(^patrole_tempest_plugin\.tests\.api)
-      tox_envlist: all-plugin
+      tox_envlist: all
+      tox_extra_args: --sitepackages
 
 - job:
     name: patrole-admin

README.rst

@@ -153,10 +153,11 @@ the steps outlined therein. Afterward, proceed with the steps below.
 
    will run the same set of tests as the default gate jobs.
 
-   You can also run Patrole tests using `tox`_. To do so, ``cd`` into the
+   You can also run Patrole tests using `tox`_, but as Patrole needs access to
+   global packages use ``--sitepackages`` argument. To do so, ``cd`` into the
    **Tempest** directory and run::
 
-     $ tox -eall-plugin -- patrole_tempest_plugin.tests.api
+     $ tox -eall --sitepackages -- patrole_tempest_plugin.tests.api
 
    .. note::