cli init throw error: write() argument must be str, not None

[yuzifeng1984]

Looks generate_default_config() in config.py already write the config.yaml and return None. No need to write file in cli.py init() further

write() argument must be str, not None
  File "/Users/yuzifeng/GitHub/PulseBot/pulsebot/cli.py", line 371, in init
    f.write(content)
  File "/Users/yuzifeng/GitHub/PulseBot/pulsebot/cli.py", line 419, in <module>
    cli()
TypeError: write() argument must be str, not None