Use oslo_debug_helper and remove our own version

With the latest version of oslotest, we can now take advantage
of a common oslo_debug_helper script.
We can now remove our own homebrewed version, minor changes to
tox.ini were needed.

Change-Id: I907f7203aefedc9b33c3dfbfecc9793e273a4a8f

test-requirements.txt

@@ -13,6 +13,7 @@ mock>=1.0
 mox3>=0.7.0
 oauthlib>=0.6
 oslosphinx>=2.2.0  # Apache-2.0
+oslotest>=1.2.0  # Apache-2.0
 pycrypto>=2.6
 requests-mock>=0.4.0  # Apache-2.0
 sphinx>=1.1.2,!=1.2.0,<1.3

tox.ini

@@ -28,9 +28,7 @@ commands = python setup.py testr --coverage --testr-args='{posargs}'
 downloadcache = ~/cache/pip
 
 [testenv:debug]
-
-commands =
- {toxinidir}/tools/debug_helper.sh {posargs}
+commands = oslo_debug_helper -t keystoneclient/tests {posargs}
 
 [flake8]
 # F821: undefined name