Add support for Faults (#360)

* FaultType - wip

* .

* copy fault

* tests

* code-factor

* more tests

* fix tests

* fixed

* remove RANDOM_DATA_THEN_CLOSE

src/WireMock.Net/ResponseMessage.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Linq;
+using WireMock.ResponseBuilders;
 using WireMock.Util;
 using WireMock.Validation;
 
@@ -35,6 +36,16 @@ namespace WireMock
         /// </summary>
         public BodyData BodyData { get; set; }
 
+        /// <summary>
+        /// The FaultType.
+        /// </summary>
+        public FaultType FaultType { get; set; }
+
+        /// <summary>
+        /// Gets or sets the Fault percentage.
+        /// </summary>
+        public double? FaultPercentage { get; set; }
+
         /// <summary>
         /// Adds the header.
         /// </summary>