Added info on semantic versioning and branching strategy to CONTRIBUTING.md

Also:
- Added isort to Pipenv dev
- Added setup.cfg to make it easy to run flake8, doc8, and isort directly from the command line without using invoke
- Ran isort to sort includes

1 files changed, 4 insertions, 3 deletions

diff --git a/tests/test_history.py b/tests/test_history.py
index 11f189f6..6fa16ad8 100755
--- a/tests/test_history.py
+++ b/tests/test_history.py
@@ -3,22 +3,23 @@
 """
 Test history functions of cmd2
 """
-import tempfile
 import os
+import tempfile
 
 import pytest
 
+import cmd2
 # Python 3.5 had some regressions in the unitest.mock module, so use
 # 3rd party mock if available
 from cmd2.parsing import StatementParser
 
+from .conftest import HELP_HISTORY, normalize, run_cmd
+
 try:
     import mock
 except ImportError:
     from unittest import mock
 
-import cmd2
-from .conftest import run_cmd, normalize, HELP_HISTORY
 
 
 #