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/exit_code.py b/examples/exit_code.py
index 89ed86cd..a35b4df8 100755
--- a/examples/exit_code.py
+++ b/examples/exit_code.py
@@ -34,6 +34,7 @@ Usage:  exit [exit_code]
 
 if __name__ == '__main__':
     import sys
+
     app = ReplWithExitCode()
     sys_exit_code = app.cmdloop()
     app.poutput('{!r} exiting with code: {}'.format(sys.argv[0], sys_exit_code))