Don't use a custom Context type

[ericchiang]

This block is particularly odd

// Context is the special context that is passed to the Handler.
// It includes:
// - Context: standard Go context that is used to pass cancellation signals and deadlines
type Context struct {
	Context context.Context
}

Are there plans to expand it? If not we should just pass additional arguments to the Handler.

[fanminshi]

No plans to expand it yet. I think we should just use default golang context type instead.

[ericchiang]

cc @Verolop

[rithujohn191]

#259 fixes this issue