Set bucket cors on creation of new installation

csharp/App/Backend/S3/S3Cmd.cs

@@ -46,8 +46,19 @@ public class S3Cmd
     
     public async Task<Boolean> CreateBucket(String bucketName)
     {
+        var cors = @"<?xml version=""1.0"" ?>
+            <CORSConfiguration xmlns=""http://s3.amazonaws.com/doc/2006-03-01/"">
+            <CORSRule>
+            <AllowedOrigin>*</AllowedOrigin>
+            <AllowedMethod>GET</AllowedMethod>
+            <AllowedMethod>HEAD</AllowedMethod>
+            <AllowedHeader>*</AllowedHeader>
+            </CORSRule>
+            </CORSConfiguration>";
         var result = await Run(bucketName, "mb");
-        return result.ExitCode == 0;
+        var setCors = await Run(bucketName, "PutBucketCors", cors);
+        
+        return result.ExitCode == 0 && setCors.ExitCode == 0;
     }
     
     public async Task<Boolean> DeleteBucket(String bucketName)