Remove all traces of nose

- No need to comment code, can be removed
- No need to set variables for code coverage in nose

Change-Id: I45c7ea488c4c2f70060022944bb4f15e7c7b68e2

tox.ini

@@ -13,7 +13,6 @@ setenv = VIRTUAL_ENV={envdir}
 
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
-#commands = nosetests {posargs}
 commands = python setup.py testr --slowest --testr-args='--concurrency 1 {posargs}'
 
 [testenv:py27]
@@ -46,7 +45,6 @@ commands =
 whitelist_externals = bash
 
 [testenv:cover]
-setenv = NOSE_WITH_COVERAGE=1
 commands =
   python setup.py testr --coverage \
     --testr-args='^(?!.*test.*coverage).*$'