Update manifest

Author: sailro

Packages/com.unity.ide.visualstudio/Editor/com.unity.ide.visualstudio.asmdef

@@ -6,7 +6,7 @@
     ],
     "excludePlatforms": [],
     "allowUnsafeCode": false,
-    "overrideReferences": true,
+    "overrideReferences": false,
     "precompiledReferences": [
         "Newtonsoft.Json.dll"
     ],

Packages/com.unity.ide.visualstudio/package.json

@@ -6,7 +6,8 @@
   "unity": "2019.4",
   "unityRelease": "25f1",
   "dependencies": {
-    "com.unity.test-framework": "1.1.9"
+    "com.unity.test-framework": "1.1.9",
+    "com.unity.nuget.newtonsoft-json": "3.0.2"
   },
   "relatedPackages": {
     "com.unity.ide.visualstudio.tests": "2.0.20"