chore(build): adjust to es6 target

Author: christianalfoni

packages/node_modules/overmind/src/views/react.ts

@@ -50,7 +50,8 @@ export default class ReactApp<
     const componentId = nextComponentId++
     let componentInstanceId = 0
     const instance = this
-    const isClassComponent = typeof Component.prototype.render === 'function'
+    const isClassComponent =
+      Component.prototype && typeof Component.prototype.render === 'function'
 
     if (isClassComponent) {
       const originalRender = Component.prototype.render