Make namespacing of executables exposed by grpc-tools packages consistent between Node and Ruby

src/node/tools/package.json

@@ -16,8 +16,8 @@
     }
   ],
   "bin": {
-    "grpc-tools-protoc": "./bin/protoc.js",
-    "grpc-tools-plugin": "./bin/protoc_plugin.js"
+    "grpc_tools_node_protoc": "./bin/protoc.js",
+    "grpc_tools_node_protoc_plugin": "./bin/protoc_plugin.js"
   },
   "scripts": {
     "install": "./node_modules/.bin/node-pre-gyp install"