Port over pretty_tox.sh from Nova

Nova has a bash script that uses the ostestr package to format
the output from tox in a 'pretty' format.  It makes it much more
readable.  pretty_tox.sh is pulled from Nova as-is and enabled
in tox.ini.

Change-Id: Ib90791b1333044c98e20444953d7ccab21cd62ba

test-requirements.txt

@@ -8,6 +8,7 @@ python-subunit
 sphinx>=1.1.2,!=1.2.0,!=1.3b1,<1.3
 oslosphinx>=2.5.0  # Apache-2.0
 oslotest>=1.5.1  # Apache-2.0
+os-testr>=0.4.1 # Apache-2.0
 testrepository>=0.0.18
 testscenarios>=0.4
 testtools>=1.4.0

tools/pretty_tox.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+
+set -o pipefail
+
+TESTRARGS=$1
+
+# --until-failure is not compatible with --subunit see:
+#
+# https://bugs.launchpad.net/testrepository/+bug/1411804
+#
+# this work around exists until that is addressed
+if [[ "$TESTARGS" =~ "until-failure" ]]; then
+    python setup.py testr --slowest --testr-args="$TESTRARGS"
+else
+    python setup.py testr --slowest --testr-args="--subunit $TESTRARGS" | subunit-trace -f
+fi

tox.ini

@@ -12,7 +12,8 @@ deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
        -egit+https://github.com/openstack/nova#egg=nova
        -egit+https://github.com/powervm/pypowervm@develop#egg=pypowervm
-commands = python setup.py testr --slowest --testr-args='{posargs}'
+whitelist_externals = bash
+commands = bash tools/pretty_tox.sh '{posargs}'
 
 [testenv:pep8]
 commands = flake8