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, 9 insertions, 0 deletions

diff --git a/cmd2/exceptions.py b/cmd2/exceptions.py
index d253985a..c5a08202 100644
--- a/cmd2/exceptions.py
+++ b/cmd2/exceptions.py
@@ -6,11 +6,13 @@
 # The following exceptions are part of the public API
 ############################################################################################################
 
+
 class SkipPostcommandHooks(Exception):
     """
     Custom exception class for when a command has a failure bad enough to skip post command
     hooks, but not bad enough to print the exception to the user.
     """
+
     pass
 
 
@@ -21,6 +23,7 @@ class Cmd2ArgparseError(SkipPostcommandHooks):
     loop, catch the SystemExit and raise this instead. If you still need to run post command hooks
     after parsing fails, just return instead of raising an exception.
     """
+
     pass
 
 
@@ -29,8 +32,10 @@ class CommandSetRegistrationError(Exception):
     Exception that can be thrown when an error occurs while a CommandSet is being added or removed
     from a cmd2 application.
     """
+
     pass
 
+
 ############################################################################################################
 # The following exceptions are NOT part of the public API and are intended for internal use only.
 ############################################################################################################
@@ -38,19 +43,23 @@ class CommandSetRegistrationError(Exception):
 
 class Cmd2ShlexError(Exception):
     """Raised when shlex fails to parse a command line string in StatementParser"""
+
     pass
 
 
 class EmbeddedConsoleExit(SystemExit):
     """Custom exception class for use with the py command."""
+
     pass
 
 
 class EmptyStatement(Exception):
     """Custom exception class for handling behavior when the user just presses <Enter>."""
+
     pass
 
 
 class RedirectionError(Exception):
     """Custom exception class for when redirecting or piping output fails"""
+
     pass