check: implement `check.Time`

[GregoryAlbouy]

Todo

• Generate interface check.Time
• Implement check.TimeCheckerProvider with the following methods (WIP suggestions):

  type TimeCheckerProvider interface {
      Is(t time.Time) TimeCheckerProvider
      Before(t time.Time) TimeCheckerProvider
      NotBefore(t time.Time) TimeCheckerProvider
      After(t time.Time) TimeCheckerProvider
      NotAfter(t time.Time) TimeCheckerProvider
      InRange(lo, hi time.Time) TimeCheckerProvider
      OutRange(lo, hi time.Time) TimeCheckerProvider
  }

• Write unit tests for check.TimeCheckerProvider

Blocks

• check: implement check.HTTPCookie #87