fix: remove useless console and clean the code

[dead-horse]

Checklist

• [ ] npm test passes
• [ ] tests and/or benchmarks are included
• [ ] documentation is changed or added
• [ ] commit message follows commit guidelines

Affected core subsystem(s)

Description of change

[codecov-io]

Codecov Report

Merging #28 into master will increase coverage by 2.38%. The diff coverage is 77.77%.

@@            Coverage Diff             @@
##           master      #28      +/-   ##
==========================================
+ Coverage   79.54%   81.92%   +2.38%     
==========================================
  Files           3        3              
  Lines          88       83       -5     
==========================================
- Hits           70       68       -2     
+ Misses         18       15       -3

Impacted Files	Coverage Δ
lib/server.js	82.81% <77.77%> (+3.1%)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 9a12f75...79e829d. Read the comment docs.

[dead-horse]

2.1.x 相对于 2.0.x 是 breaking change（node 版本不兼容），建议后续发版本需要注意 semver，否则这个模块别人很难用于生产。

[Azard]

@dead-horse 我会注意的，感谢

[dead-horse]

这个不应该发 2.2.0 吧，没有新增 feature