Merge "fix tox python3 overrides"

tox.ini

@@ -25,6 +25,7 @@ whitelist_externals = find
                       rm
 
 [testenv:debug]
+basepython = python3
 commands = oslo_debug_helper -t troveclient/tests {posargs}
 
 [testenv:debug-py27]
@@ -36,12 +37,15 @@ basepython = python3.5
 commands = oslo_debug_helper -t troveclient/tests {posargs}
 
 [testenv:pep8]
+basepython = python3
 commands = flake8
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
 commands =
     coverage erase
     python setup.py testr --coverage --testr-args='{posargs}'
@@ -49,6 +53,7 @@ commands =
     coverage report
 
 [testenv:docs]
+basepython = python3
 deps =
        -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
        -r{toxinidir}/requirements.txt
@@ -58,6 +63,7 @@ commands =
   sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:releasenotes]
+basepython = python3
 deps =
        -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
        -r{toxinidir}/requirements.txt