Adds support for root context redirection

core/pkg/ingress/defaults/main.go

@@ -6,6 +6,8 @@ import "net"
 // The reason of this requirements is the annotations are generic. If some implementation do not supports
 // one or more annotations it just can provides defaults
 type Backend struct {
+	// AppRoot contains the AppRoot for apps that doesn't exposes its content in the 'root' context
+	AppRoot string `json:"app-root"`
 
 	// enables which HTTP codes should be passed for processing with the error_page directive
 	// http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_intercept_errors