add test for json serialize

src/ResourceQuantity.cs

@@ -83,7 +83,7 @@ namespace k8s.Models
     ///     writing some sort of special handling code in the hopes that that will
     ///     cause implementors to also use a fixed point implementation.
     /// </summary>
-    [JsonConverter(typeof(IntOrStringConverter))]
+    [JsonConverter(typeof(QuantityConverter))]
     public partial class ResourceQuantity
     {
         public enum SuffixFormat

tests/QuantityValueTests.cs

@@ -1,5 +1,6 @@
 using System;
 using k8s.Models;
+using Newtonsoft.Json;
 using Xunit;
 using static k8s.Models.ResourceQuantity.SuffixFormat;
 
@@ -7,6 +8,15 @@ namespace k8s.Tests
 {
     public class QuantityValueTests
     {
+        [Fact]
+        public void Deserialize()
+        {
+            {
+                var q = JsonConvert.DeserializeObject<ResourceQuantity>("\"12k\"");
+                Assert.Equal(new ResourceQuantity(12000, 0, DecimalSI), q);
+            }
+        }
+
         [Fact]
         public void Parse()
         {
@@ -215,5 +225,14 @@ namespace k8s.Tests
                 Assert.Equal(expect, new ResourceQuantity(alternate).ToString());
             }
         }
+
+        [Fact]
+        public void Serialize()
+        {
+            {
+                ResourceQuantity quantity = 12000;
+                Assert.Equal("\"12e3\"", JsonConvert.SerializeObject(quantity));
+            }
+        }
     }
 }