WebP Server Go 0.13.1

What's Changed

• Added --verbosity flag by @n0vad3v in #375

Now you can control log level using --verbosity flag on startup, e,g: ./webp-server --verbosity 0

0 = silent (no log messages)
1 = error (error messages only)
2 = warn (error messages and warnings only)
3 = info (error messages, warnings and normal activity logs)
4 = debug (all info plus additional messages for debugging)

Full Changelog: 0.13.0...0.13.1