var siteExtension = new TemplateDeployment("nr-ext", new TemplateDeploymentArgs
            {
                DeploymentMode = "Incremental",
                ResourceGroupName = rgname,
                TemplateBody = File.ReadAllText("siteextension.json"),
                Parameters = {{"siteName", app.Name}, {"extensionName", "NewRelic.Azure.WebSites.Extension" }, {"extensionVersion", "1.5.0"} }
            });