Adds pre-commit config to run various lintersci_improvements

This ads black, isort, pyupgrade, and flake8 to pre-commit-config.yaml
There are also some small changes to travis.yml and tasks.py to reduce
some repeated configurations that should be consolidated into
setup.cfg. Most other changes are automated by the linter scripts.

1 files changed, 1 insertions, 0 deletions

diff --git a/examples/custom_parser.py b/examples/custom_parser.py
index 34c7bee2..fa21a0b4 100644
--- a/examples/custom_parser.py
+++ b/examples/custom_parser.py
@@ -10,6 +10,7 @@ from cmd2 import Cmd2ArgumentParser, ansi, set_default_argument_parser
 # First define the parser
 class CustomParser(Cmd2ArgumentParser):
     """Overrides error class"""
+
     def __init__(self, *args, **kwargs) -> None:
         super().__init__(*args, **kwargs)