Remove default tox_envlist: venv

Setting tox_envlist to venv by default is unintuitive for
many users. Remove this behaviour and let default tox
behaviour be the same as running tox on the commandline.

Change-Id: I1b6d59ee4ebb7f6b3adcf4bd35d7148e83389008

roles/fetch-tox-output/README.rst

@@ -3,7 +3,6 @@ Collect log output from a tox build
 **Role Variables**
 
 .. zuul:rolevar:: tox_envlist
-   :default: venv
 
     Comma separated string with test environmens to fetch log output from.
     ``ALL`` fetches all environments while an empty string fetches all test

roles/fetch-tox-output/defaults/main.yaml

@@ -1,7 +1,4 @@
 ---
-# TODO(mordred) This needs to switch back to not being venv - venv is OpenStack
-# specific.
-tox_envlist: venv
 tox_executable: tox
 
 zuul_work_dir: "{{ zuul.project.src_dir }}"

roles/tox/README.rst

@@ -7,7 +7,6 @@ Runs tox for a project
    Environment variables to pass in to the tox run.
 
 .. zuul:rolevar:: tox_envlist
-   :default: venv
 
    Comma separated string with test environments tox should run.
    ``ALL`` runs all test environments while an empty string runs

roles/tox/defaults/main.yaml

@@ -1,6 +1,5 @@
 ---
 tox_environment: {}
-tox_envlist: venv
 tox_executable: tox
 tox_extra_args: -vv
 tox_install_siblings: true

test-playbooks/python/tox.yaml

@@ -1,4 +1,6 @@
 - hosts: all
+  roles:
+    - ensure-tox
   tasks:
     - name: Run bindep
       include_role: