title: ImportError: cannot import name 'types' from 'google.cloud.vision' though I have google cloud vision installed
body: <p>I have installed google-cloud-vision library following the documentation. It is for some reason unable to import <code>types</code> from <code>google.cloud.vision</code>. It worked fine on my pc, now when I shared with my client, he had a problem with imports though he has the library installed via pip. Here's the line that throws error:</p>
  <pre class="lang-py prettyprint-override"><code>from google.cloud import vision
  from google.cloud.vision import types # this line throws error
  </code></pre>
  <p>Any idea how to resolve this issue?</p>