remove experimental-handlers examples, users should visit github.com/iris-contrib/middleware instead, let's not have duplications

Former-commit-id: 72754683d1bcd4325b5fcd9f57c6cb87f1d7337d

_examples/experimental-handlers/prometheus/simple/main.go

@@ -1,40 +0,0 @@
-package main
-
-import (
-	"math/rand"
-	"time"
-
-	"github.com/kataras/iris"
-
-	prometheusMiddleware "github.com/iris-contrib/middleware/prometheus"
-
-	"github.com/prometheus/client_golang/prometheus/promhttp"
-)
-
-func main() {
-	app := iris.New()
-	m := prometheusMiddleware.New("serviceName", 300, 1200, 5000)
-
-	app.Use(m.ServeHTTP)
-
-	app.OnErrorCode(iris.StatusNotFound, func(ctx iris.Context) {
-		// error code handlers are not sharing the same middleware as other routes, so we have
-		// to call them inside their body.
-		m.ServeHTTP(ctx)
-
-		ctx.Writef("Not Found")
-	})
-
-	app.Get("/", func(ctx iris.Context) {
-		sleep := rand.Intn(4999) + 1
-		time.Sleep(time.Duration(sleep) * time.Millisecond)
-		ctx.Writef("Slept for %d milliseconds", sleep)
-	})
-
-	app.Get("/metrics", iris.FromStd(promhttp.Handler()))
-
-	// http://localhost:8080/
-	// http://localhost:8080/anotfound
-	// http://localhost:8080/metrics
-	app.Run(iris.Addr(":8080"))
-}