Replace nose with testr

- add .testr.conf (in base dir and nova_tests)
- remove all references to nose
- adjust paths: A couple of tests would assume the current directory
  was ./tests/ but it is now ./
- don't run the tests in parallel as the db tests have one connection
  per test class.

nova_tests hackery:
It seems testtools/testr imports everything and I just don't see a way of
running things in tests/ and nova_tests/ seperately but in one .test.conf.
So if you want to use testr directly you will need to:
 testr run
 cd nova_tests
 testr run

part of bug 1177924
Change-Id: I41875dcf94463fa5f9c07a7840c37089226c59ad

tox.ini

@@ -5,18 +5,16 @@ envlist = py26,py27,pep8
 deps = -r{toxinidir}/tools/test-requires
        -r{toxinidir}/tools/pip-requires
 setenv = VIRTUAL_ENV={envdir}
-         NOSE_WITH_OPENSTACK=1
-         NOSE_OPENSTACK_COLOR=1
-         NOSE_OPENSTACK_RED=0.05
-         NOSE_OPENSTACK_YELLOW=0.025
-         NOSE_OPENSTACK_SHOW_ELAPSED=1
+         EVENTLET_NO_GREENDNS=yes
 commands =
-    nosetests --no-path-adjustment --where=../nova_tests
-    nosetests --no-path-adjustment {posargs}
+   python setup.py testr --slowest --testr-args='--concurrency=1 {posargs}'
+   bash tools/init_testr_if_needed.sh
+   python setup.py testr --slowest --testr-args='--concurrency=1 --here=nova_tests {posargs}'
 sitepackages = False
 
 [testenv:cover]
-commands = nosetests --no-path-adjustment --with-coverage --cover-erase --cover-package=ceilometer --cover-inclusive []
+setenv = VIRTUAL_ENV={envdir}
+commands = python setup.py testr --coverage
 
 [testenv:pep8]
 # Install bounded pep8/pyflakes first, then let flake8 install