title: Authentication issue with R's bigrquery
body: <p><a href="https://stackoverflow.com/questions/42410147/how-to-authenticate-with-service-account-and-bigrquery-package">This post</a> makes it clear that the function <code>bq_auth()</code> should be used to authenticate BigQuery in R. However, I have created a BigQuery-Admin service account, downloaded a service account key, and have passed that key into the <code>bq_auth()</code> function, yet I continue to receive the error:</p>
  
  <pre><code>&gt; bigrquery::bq_auth(path = '/Users/nicholas/Downloads/just_downladed_this_key.json')
  trying token_fetch()
  trying credentials_service_account()
  adding 'userinfo.email' scope
  Error: unable to load shared object '/Library/Frameworks/R.framework/Versions/3.5/Resources/library/openssl/libs/openssl.so':
    dlopen(/Library/Frameworks/R.framework/Versions/3.5/Resources/library/openssl/libs/openssl.so, 6): Library not loaded: /usr/local/opt/openssl/lib/libssl.1.0.0.dylib
    Referenced from: /Library/Frameworks/R.framework/Versions/3.5/Resources/library/openssl/libs/openssl.so
    Reason: image not found
  trying credentials_app_default()
  file exists at ADC path: /Users/nicholas/.config/gcloud
  Error: parse error: premature EOF
  
                       (right here) ------^
  
  trying credentials_gce()
  Error: argument is of length zero
  trying credentials_byo_oauth()
  Error: inherits(token, "Token2.0") is not TRUE
  trying credentials_user_oauth2()
  Gargle2.0 initialize
  attempt from: bigrquery
  adding 'userinfo.email' scope
  loading token from the cache
  Error: unable to load shared object '/Library/Frameworks/R.framework/Versions/3.5/Resources/library/openssl/libs/openssl.so':
    dlopen(/Library/Frameworks/R.framework/Versions/3.5/Resources/library/openssl/libs/openssl.so, 6): Library not loaded: /usr/local/opt/openssl/lib/libssl.1.0.0.dylib
    Referenced from: /Library/Frameworks/R.framework/Versions/3.5/Resources/library/openssl/libs/openssl.so
    Reason: image not found
  </code></pre>
  
  <p>It looks like I've got an openssl / libssl issue on my hands...</p>