title: References from Python Bigquery Client don't work
body: <p>Im having troubles running the following code:</p>
  
  <pre><code>from google.cloud import bigquery
  client = bigquery.Client.from_service_account_json(BQJSONKEY,project = BQPROJECT)
  dataset = client.dataset(BQDATASET)
  assert not dataset.exists() 
  </code></pre>
  
  <p>The following error pop up:
  <code>'DatasetReference' object has no attribute 'exists'</code></p>
  
  <p>Similarly when i do:</p>
  
  <p><code>table = dataset.table(BQTABLE)</code></p>
  
  <p>i get: <code>'TableReference' object has no attribute 'exists'</code></p>
  
  <p>However, according to the docs it should work:
  <a href="https://googlecloudplatform.github.io/google-cloud-python/stable/bigquery/usage.html#datasets" rel="nofollow noreferrer">https://googlecloudplatform.github.io/google-cloud-python/stable/bigquery/usage.html#datasets</a></p>
  
  <p>here is my <code>pip freeze</code> (the part with google-cloud):</p>
  
  <pre><code>gapic-google-cloud-datastore-v1==0.15.3
  gapic-google-cloud-error-reporting-v1beta1==0.15.3
  gapic-google-cloud-logging-v2==0.91.3
  gevent==1.2.2
  glob2==0.5
  gmpy2==2.0.8
  google-api-core==0.1.1
  google-auth==1.2.1
  google-cloud==0.30.0
  google-cloud-bigquery==0.28.0
  google-cloud-bigtable==0.28.1
  google-cloud-core==0.28.0
  google-cloud-datastore==1.4.0
  google-cloud-dns==0.28.0
  google-cloud-error-reporting==0.28.0
  google-cloud-firestore==0.28.0
  google-cloud-language==1.0.0
  google-cloud-logging==1.4.0
  google-cloud-monitoring==0.28.0
  google-cloud-pubsub==0.29.1
  google-cloud-resource-manager==0.28.0
  google-cloud-runtimeconfig==0.28.0
  google-cloud-spanner==0.29.0
  google-cloud-speech==0.30.0
  google-cloud-storage==1.6.0
  google-cloud-trace==0.16.0
  google-cloud-translate==1.3.0
  google-cloud-videointelligence==0.28.0
  google-cloud-vision==0.28.0
  google-gax==0.15.16
  google-resumable-media==0.3.1
  googleapis-common-protos==1.5.3
  </code></pre>
  
  <p>I wonder how can i fix it and make it work?</p>