title: UWP "Access to the path '...' is denied" when trying to write a json file to the app directory
body: <p>I'm new to UWP, but I've been using C# (desktop applications, etc) for a long time. I recently tried writing to a json file in the app directory like I usually would, and I got this message:</p>
  
  <pre><code>Access to the path 'C:\...\setting.json' is denied
  </code></pre>
  
  <p>This was the code I was using:</p>
  
  <pre><code>File.WriteAllText(Path.Combine(Directory.GetCurrentDirectory(), "setting.json"), JsonConvert.SerializeObject(Settings));
  </code></pre>
  
  <p>I though that was weird so I did some research. It seems the app directory is read-only. I've tried setting the attribute to "Normal", still the same error. I've tried using StorageFolder and StorageFile, still the same message. Is there some way to make the folder not read-only? This worked just fine in a WPF app...</p>