Roadmap to v2

[xen0n]

• 切出 v2 分支
• 提升最低 Go 版本要求，提升一些期待已久的依赖库版本
• 开始引入 API-breaking changes [1/n] Version 2 breaking changes #133
• Tag RC
• 等下游正面反馈
• Release

在 tag 出 v2.0.0 之前不预期出现任何问题。如果有，及时过来冒泡

[xen0n]

Time flies like an arrow!

Instead of indefinitely blocking progress and driving people away from the project, let's just start moving and merge things gradually.

Roadmap pulled out of #133:

• Cleanups
  • General Go Generics cleanups
  • Fix Chinglish
  • Fix things like Id
• WorkwxFoo -> WeComFoo (with compatibility aliases)
• Access token provider (允许自由替换Token生成逻辑 #72)
• Low-level API design (希望能返回微信接口的响应 #55)
• Provide an easy-to-use global instance in a separate package & corresponding docs (discovered by looking at many usages in the wild)