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/tasks.py b/tasks.py
index ed0004a6..f95a42c0 100644
--- a/tasks.py
+++ b/tasks.py
@@ -15,6 +15,7 @@ import sys
 
 import invoke
 
+
 # shared function
 def rmrf(items, verbose=True):
     "Silently remove a list of directories or files"