[feat] Update `accepts` module

[mahnunchik]

Describe the feature

Please update accepts module to version 2.0.0 https://github.com/jshttp/accepts/releases/tag/2.0.0

└─┬ koa@3.0.1
  ├─┬ accepts@1.3.8
  │ └── mime-types@2.1.35
  ├── mime-types@3.0.1

Checklist

• I have searched through GitHub issues for similar issues.
• I have completely read through the README and documentation.

[chunlampang]

I think mime-types should be downgrade first #1900

[mahnunchik]

It should be fixed in mime-types jshttp/mime-types@7c3c63d

[chunlampang]

After 2 months, neither koa nor mime-types has taken any action. :(