Pynvim 0.4.1

Logging will be disabled on release tarballs and pip packages for performance reasons. use scripts/enable_log_statements.sh and scripts/disable_log_statements.sh to toggle the availability of logging.

Changes since 0.4.0:

• 09bba08 remove scrutinizer
• f048531 make pytest_runner an optional dependency
• 5b50ce9 fix missing self.name for nvim_error_event
• 175a2cc Test with python 3.8
• 5a2b552 fix the disable logging script.