fix to f# controller

Author: isaacrlevin

src/ProjectTemplates/Web.ProjectTemplates/content/WebApi-FSharp/Controllers/WeatherController.fs

@@ -22,11 +22,11 @@ type WeatherController () =
     inherit ControllerBase()
 
     [<HttpGet>]
-    member this.Get(location:string, unit: string) =
+    member this.Get(location:string, unit: TemperatureUnit) =
         let rnd = System.Random()
         let result:WeatherResult = {
             Location = location;
             Temperature = rnd.Next(-20,55);
             TemperatureUnit = unit
         }
-        ActionResult<WeatherResult>(result)
+        ActionResult<WeatherResult>(result)