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, 1 insertions, 0 deletions

diff --git a/examples/unicode_commands.py b/examples/unicode_commands.py
index f8381e50..0a7c5ac7 100755
--- a/examples/unicode_commands.py
+++ b/examples/unicode_commands.py
@@ -3,6 +3,7 @@
 """A simple example demonstrating support for unicode command names.
 """
 import math
+
 import cmd2