Add support for verification process

Add required configuration files and generally update the interface
after move to OpenStack git/gerrit.

Change-Id: I5c14ad429a0bb11902ab0352707da877390c0688

.gitreview

@@ -0,0 +1,4 @@
+[gerrit]
+host=review.openstack.org
+port=29418
+project=openstack/charm-interface-keystone-credentials

interface.yaml

@@ -13,4 +13,4 @@ summary: >
                              Defaults to Admin role.
            domain: Keystone v3 domain the user will be created in. Defaults
                    to the Default domain.
-maintainer: OpenStack Charmers <openstack-charmers@lists.ubuntu.com>
+maintainer: OpenStack Charmers <openstack-dev@lists.openstack.org>

test-requirements.txt

@@ -1,3 +1,2 @@
 flake8>=2.2.4,<=2.4.1
 os-testr>=0.4.1
-charm-tools

tox.ini

@@ -1,6 +1,7 @@
 [tox]
-envlist = lint,py27
+envlist = pep8,py27,py34,py35
 skipsdist = True
+skip_missing_interpreters = True
 
 [testenv]
 setenv = VIRTUAL_ENV={envdir}
@@ -12,8 +13,22 @@ commands = ostestr {posargs}
 [testenv:py27]
 basepython = python2.7
 deps = -r{toxinidir}/test-requirements.txt
+# TODO: Need to write unit tests then remove the following command.
+commands = /bin/true
 
-[testenv:lint]
+[testenv:py34]
+basepython = python3.4
+deps = -r{toxinidir}/test-requirements.txt
+# TODO: Need to write unit tests then remove the following command.
+commands = /bin/true
+
+[testenv:py35]
+basepython = python3.5
+deps = -r{toxinidir}/test-requirements.txt
+# TODO: Need to write unit tests then remove the following command.
+commands = /bin/true
+
+[testenv:pep8]
 basepython = python2.7
 deps = -r{toxinidir}/test-requirements.txt
 commands = flake8 {posargs}