Add support for submit option on Dispute update

src/Stripe.net/Services/Disputes/DisputeUpdateOptions.cs

@@ -5,10 +5,29 @@ namespace Stripe
 
     public class DisputeUpdateOptions : BaseOptions
     {
+        /// <summary>
+        /// Evidence to upload, to respond to a dispute. Updating any field in the hash will submit
+        /// all fields in the hash for review. The combined character count of all fields is
+        /// limited to 150,000.
+        /// </summary>
         [JsonProperty("evidence")]
         public DisputeEvidenceOptions Evidence { get; set; }
 
+        /// <summary>
+        /// A set of key/value pairs that you can attach to a charge object. It can be useful for
+        /// storing additional information about the customer in a structured format. It's often a
+        /// good idea to store an email address in metadata for tracking later.
+        /// </summary>
         [JsonProperty("metadata")]
         public Dictionary<string, string> Metadata { get; set; }
+
+        /// <summary>
+        /// Whether to immediately submit evidence to the bank. If <code>false</code>, evidence is
+        /// staged on the dispute. Staged evidence is visible in the API and Dashboard, and can be
+        /// submitted to the bank by making another request with this attribute set to
+        /// <code>true</code> (the default).
+        /// </summary>
+        [JsonProperty("submit")]
+        public bool? Submit { get; set; }
     }
 }