* pre-commit run trailing-whitespace -a
* pre-commit run end-of-file-fixer -a
* pre-commit run double-quote-string-fixer -a
* pre-commit run requirements-txt-fixer -a
* add pyupgrade hook
* remove pre-commit default_language_version 3.7 (since no upwards incompatible hooks)
Automatic fixes produced by yapf formatting using `--style=google`, as
well as common pre-commit checks such as trailing whitespace removal,
double quote fixer, and newlines at the end of a file.
Adds a pre-commit config for development that runs several fixers, including YAPF with
"google" style and pylint for static analysis.
Use of `requirements-dev.txt` appears to be a common pattern for this
type of work:
https://pypi.org/project/requirements-dev.txt/
