reorganization of _examples and add some new examples such as iris+groupcache+mysql+docker

Former-commit-id: ed635ee95de7160cde11eaabc0c1dcb0e460a620

_examples/file-server/upload-files/main_test.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"os"
+	"testing"
+
+	"github.com/kataras/iris/v12/httptest"
+)
+
+func TestUploadFiles(t *testing.T) {
+	app := newApp()
+	e := httptest.New(t, app)
+
+	// upload the file itself.
+	fh, err := os.Open("main.go")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer fh.Close()
+
+	e.POST("/upload").WithMultipart().WithFile("files", "main.go", fh).
+		Expect().Status(httptest.StatusOK)
+
+	f, err := os.Open("uploads/main.go")
+	if err != nil {
+		t.Fatalf("expected file to get actually uploaded on the system directory but: %v", err)
+	}
+	f.Close()
+
+	os.Remove(f.Name())
+}