added functions to bench

functions/helloget.go

@@ -0,0 +1,10 @@
+package kubeless
+
+import (
+	"github.com/kubeless/kubeless/pkg/functions"
+)
+
+// Foo sample function
+func Foo(event functions.Event, context functions.Context) (string, error) {
+	return "Hello world!", nil
+}