Specify testenv command for tox>=2.5

As of the tox 2.5.0 release, failure to specify a default commands
key in the fallback testenv section of tox.ini instantly fails with
"ERROR: Commands not specified. Please update relevant section of
.../tox.ini".

Copy the testenv.commands entry from the openstack/cookiecutter
repo's template. While at it, copy the boilerplate placeholder test
from the cookiecutter templates so that jobs don't freak out when
they discover (and then run) no tests.

Change-Id: Ifb8fcfbb6d76edd8c7dcf814a705ee7eff3a9819

.testr.conf

@@ -1,4 +1,7 @@
 [DEFAULT]
-test_command=OS_STDOUT_CAPTURE=${OS_STDOUT_CAPTURE:-1} OS_STDERR_CAPTURE=${OS_STDERR_CAPTURE:-1} OS_LOG_CAPTURE=${OS_LOG_CAPTURE:-1} ${PYTHON:-python} -m subunit.run discover -t ./ tests $LISTOPT $IDOPTION
+test_command=OS_STDOUT_CAPTURE=${OS_STDOUT_CAPTURE:-1} \
+             OS_STDERR_CAPTURE=${OS_STDERR_CAPTURE:-1} \
+             OS_TEST_TIMEOUT=${OS_TEST_TIMEOUT:-60} \
+             ${PYTHON:-python} -m subunit.run discover -t ./ . $LISTOPT $IDOPTION
 test_id_option=--load-list $IDFILE
 test_list_option=--list

gerritlib/tests/base.py

@@ -0,0 +1,5 @@
+import testtools
+
+
+class TestCase(testtools.TestCase):
+    "Placeholder wrapper for the testtools.TestCase class."

gerritlib/tests/test_gerritlib.py

@@ -0,0 +1,28 @@
+# -*- coding: utf-8 -*-
+
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+"""
+test_gerritlib
+----------------------------------
+
+Tests for `gerritlib` module.
+"""
+
+from gerritlib.tests import base
+
+
+class TestGerritlib(base.TestCase):
+
+    def test_something(self):
+        pass

test-requirements.txt

@@ -2,3 +2,4 @@ hacking>=0.5.6,<0.11
 sphinx>=1.1.2,<1.2
 python-subunit
 testrepository
+testtools

tox.ini

@@ -4,6 +4,7 @@ skipdist = True
 envlist = pep8, py27, pypy, py33, py34
 
 [testenv]
+commands = python setup.py test --slowest --testr-args='{posargs}'
 setenv = VIRTUAL_ENV={envdir}
 usedevelop = True
 install_command = pip install {opts} {packages}