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: https://github.com/openstack/tempest/blob/9b4c50cf634cbea6e6a7353fff14c2f0a7ab1aa2/tox.ini#L64

Depends-On: Ib3264f54075216471720483c8dd816887c1f413c
Change-Id: I440b6cff2b5378e18304017589e3e7cf4748c28c
diff --git a/README.rst b/README.rst
index 6ca3747..31cd3b7 100644
--- a/README.rst
+++ b/README.rst
@@ -153,10 +153,11 @@
 
    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::