Python 3 only

Remove need for six library not used anymore.
Use unittest mock instead of third party mock.

Also add .stestr to gitignore.

Change-Id: Id9b72b1169d225a78bf7e160ecebb6f6b8f8c3be

.gitignore

@@ -102,3 +102,6 @@ venv.bak/
 
 # mypy
 .mypy_cache/
+
+# Unit test
+.stestr/

lower-constraints.txt

@@ -16,7 +16,6 @@ keystoneauth1==3.4.0
 linecache2==1.0.0
 MarkupSafe==1.0
 mccabe==0.2.1
-mock==2.0.0
 mox3==0.20.0
 openstackdocstheme==1.18.1
 os-client-config==1.28.0
@@ -33,7 +32,6 @@ PyYAML==3.12
 reno==2.5.0
 requests==2.14.2
 requestsexceptions==1.2.0
-six==1.10.0
 snowballstemmer==1.2.1
 Sphinx==1.6.2
 sphinxcontrib-websupport==1.0.1

requirements.txt

@@ -4,5 +4,4 @@
 
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
 python-dateutil>=2.7.0 # BSD
-six>=1.10.0 # MIT
 sushy>=2.0.0 # Apache-2.0

setup.cfg

@@ -14,6 +14,7 @@ classifier =
     License :: OSI Approved :: Apache Software License
     Operating System :: POSIX :: Linux
     Programming Language :: Python
+    Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7

sushy_oem_idrac/tests/unit/test_manager.py

@@ -14,8 +14,8 @@
 #    under the License.
 
 import json
+from unittest import mock
 
-import mock
 from oslotest.base import BaseTestCase
 import sushy
 from sushy.resources.manager import manager

sushy_oem_idrac/tests/unit/test_root.py

@@ -14,8 +14,8 @@
 #    under the License.
 
 import json
+from unittest import mock
 
-import mock
 from oslotest.base import BaseTestCase
 from sushy import main