third_party/protobuf: Update to HEAD (83d681ee2c)

third_party/protobuf/csharp/src/Google.Protobuf.Conformance/project.json

Index: third_party/protobuf/csharp/src/Google.Protobuf.Conformance/project.json
diff --git a/third_party/protobuf/csharp/src/Google.Protobuf.Conformance/project.json b/third_party/protobuf/csharp/src/Google.Protobuf.Conformance/project.json
new file mode 100644
index 0000000000000000000000000000000000000000..84b23c456d515861490f19fb4644b5bb66236851
--- /dev/null
+++ b/third_party/protobuf/csharp/src/Google.Protobuf.Conformance/project.json
@@ -0,0 +1,19 @@
+{
+  "buildOptions": {
+    "debugType": "portable",
+    "emitEntryPoint": true
+  },
+  "dependencies": {
+    "Google.Protobuf": { "target": "project" }
+  },
+  "frameworks": {
+    "netcoreapp1.0": {
+      "dependencies": {
+        "Microsoft.NETCore.App": {
+          "type": "platform",
+          "version": "1.0.0"
+        }
+      }
+    }
+  }
+}