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, 3 insertions, 2 deletions

diff --git a/cmd2/__init__.py b/cmd2/__init__.py
index 81e80efe..1f122b87 100644
--- a/cmd2/__init__.py
+++ b/cmd2/__init__.py
@@ -20,9 +20,11 @@ from .argparse_custom import Cmd2ArgumentParser, Cmd2AttributeWrapper, Completio
 
 # Check if user has defined a module that sets a custom value for argparse_custom.DEFAULT_ARGUMENT_PARSER
 import argparse
+
 cmd2_parser_module = getattr(argparse, 'cmd2_parser_module', None)
 if cmd2_parser_module is not None:
     import importlib
+
     importlib.import_module(cmd2_parser_module)
 
 # Get the current value for argparse_custom.DEFAULT_ARGUMENT_PARSER
@@ -30,8 +32,7 @@ from .argparse_custom import DEFAULT_ARGUMENT_PARSER
 from .cmd2 import Cmd
 from .command_definition import CommandSet, with_default_category
 from .constants import COMMAND_NAME, DEFAULT_SHORTCUTS
-from .decorators import with_argument_list, with_argparser, with_argparser_and_unknown_args, with_category, \
-    as_subcommand_to
+from .decorators import with_argument_list, with_argparser, with_argparser_and_unknown_args, with_category, as_subcommand_to
 from .exceptions import Cmd2ArgparseError, SkipPostcommandHooks, CommandSetRegistrationError
 from . import plugin
 from .parsing import Statement