Check arguments to __dynamicImport method call.

This prevents the audit-argument-checks package from complaining about
this method in production.

packages/dynamic-import/package.js

@@ -12,6 +12,7 @@ Package.onUse(function (api) {
   api.use("localstorage");
   api.use("promise");
   api.use("ddp");
+  api.use("check");
   api.use("ecmascript", "server");
   api.mainModule("client.js", "client");
   api.mainModule("server.js", "server");

packages/dynamic-import/server.js

@@ -5,6 +5,8 @@ import {
   normalize as pathNormalize,
 } from "path";
 
+import { check } from "meteor/check";
+
 import "./security.js";
 import "./client.js";
 
@@ -19,6 +21,8 @@ Object.keys(dynamicImportInfo).forEach(platform => {
 
 Meteor.methods({
   __dynamicImport(tree) {
+    check(tree, Object);
+
     const platform = this.connection ? "web.browser" : "server";
     const pathParts = [];