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, 4 insertions, 0 deletions

diff --git a/cmd2/plugin.py b/cmd2/plugin.py
index 83093ee1..e836b9d1 100644
--- a/cmd2/plugin.py
+++ b/cmd2/plugin.py
@@ -7,6 +7,7 @@ import attr
 @attr.s
 class PostparsingData:
     """Data class containing information passed to postparsing hook methods"""
+
     stop = attr.ib()
     statement = attr.ib()
 
@@ -14,12 +15,14 @@ class PostparsingData:
 @attr.s
 class PrecommandData:
     """Data class containing information passed to precommand hook methods"""
+
     statement = attr.ib()
 
 
 @attr.s
 class PostcommandData:
     """Data class containing information passed to postcommand hook methods"""
+
     stop = attr.ib()
     statement = attr.ib()
 
@@ -27,5 +30,6 @@ class PostcommandData:
 @attr.s
 class CommandFinalizationData:
     """Data class containing information passed to command finalization hook methods"""
+
     stop = attr.ib()
     statement = attr.ib()