Add nose to run_tests and tox for python 2.6

This commit adds python 2.6 to both tox and run_tests. 2 new tox jobs
are added py26-full and py26-smoke, which will use nose as the test
runner. run_tests.sh is also modified to detect whether python2.6 is
being used, and if so it will use nose instead of testr.

Change-Id: Ia7cecbea99ba2f995a726def6f775a313c4e94ba
diff --git a/tox.ini b/tox.ini
index dc8980d..471fecb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -27,6 +27,29 @@
 commands =
   sh tools/pretty_tox.sh '(?!.*\[.*\bslow\b.*\])(^tempest\.(api|scenario|thirdparty|cli)) {posargs}'
 
+[testenv:py26-full]
+sitepackages = True
+setenv = VIRTUAL_ENV={envdir}
+         NOSE_WITH_OPENSTACK=1
+         NOSE_OPENSTACK_COLOR=1
+         NOSE_OPENSTACK_RED=15
+         NOSE_OPENSTACK_YELLOW=3
+         NOSE_OPENSTACK_SHOW_ELAPSED=1
+         NOSE_OPENSTACK_STDOUT=1
+commands =
+  nosetests --logging-format '%(asctime)-15s %(message)s' --with-xunit -sv --xunit-file=nosetests-full.xml tempest/api tempest/scenario tempest/thirdparty tempest/cli {posargs}
+
+[testenv:py26-smoke]
+setenv = VIRTUAL_ENV={envdir}
+NOSE_WITH_OPENSTACK=1
+         NOSE_OPENSTACK_COLOR=1
+         NOSE_OPENSTACK_RED=15
+         NOSE_OPENSTACK_YELLOW=3
+         NOSE_OPENSTACK_SHOW_ELAPSED=1
+         NOSE_OPENSTACK_STDOUT=1
+commands =
+  nosetests --logging-format '%(asctime)-15s %(message)s' --with-xunit -sv --attr=type=smoke --xunit-file=nosetests-smoke.xml tempest {posargs}
+
 [testenv:smoke]
 sitepackages = True
 setenv = VIRTUAL_ENV={envdir}