title: `docker-credential-gcloud` not in system PATH
body: <p>After the latest updates to gcloud and docker I'm unable to access images on my google container repository.  Locally when I run: <code>gcloud auth configure-docker</code> as per the instructions after updating gcloud, I get the following message:</p>
  
  <pre><code>WARNING: `docker-credential-gcloud` not in system PATH.
  gcloud's Docker credential helper can be configured but it will not work until this is corrected.
  gcloud credential helpers already registered correctly.
  </code></pre>
  
  <p>Running <code>which docker-credential-gcloud</code> returns <code>docker-credential-gcloud not found</code>.</p>
  
  <p>I have no other gcloud-related path issues and for the life of me can't figure out how to install/add docker-credential-gcloud to path. Here's what I have installed (shown via <code>gcloud version</code>):</p>
  
  <pre><code>Google Cloud SDK 197.0.0
  beta 2017.09.15
  bq 2.0.31
  container-builder-local
  core 2018.04.06
  docker-credential-gcr
  gsutil 4.30
  </code></pre>
  
  <p>I also have Docker CE Version 18.03.0-ce-mac60 (23751).</p>
  
  <p>Here's my $PATH:<code>/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin</code></p>
  
  <p>I also ran <code>source /usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/path.zsh.inc</code> on original gcloud install.</p>