Migrate to tonic

proto/helloworld.proto

@@ -0,0 +1,17 @@
+syntax = "proto3";
+package helloworld;
+
+service Greeter {
+  // Our SayHello rpc accepts HelloRequests and returns HelloReplies
+  rpc SayHello (HelloRequest) returns (HelloReply);
+}
+
+message HelloRequest {
+  // Request message contains the name to be greeted
+  string name = 1;
+}
+
+message HelloReply {
+  // Reply contains the greeting message
+  string message = 1;
+}