Only export delay settings if actually used

go/fake-http/fake-http.go

	Headers []Header `yaml:"headers"`
	Body    string   `yaml:"body"`
	Delay       time.Duration `yaml:"delay"`
	RandomDelay time.Duration `yaml:"randomDelay"`
	Delay       time.Duration `yaml:"delay,omitempty"`
	RandomDelay time.Duration `yaml:"randomDelay,omitempty"`
}
// AsHTTP returns a http.Response representation.