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/alias_startup.py b/examples/alias_startup.py
index 052d1367..3fa9ec5a 100755
--- a/examples/alias_startup.py
+++ b/examples/alias_startup.py
@@ -5,6 +5,7 @@
     2) How to run an initialization script at startup
 """
 import os
+
 import cmd2