title: Unable to use bigrquery with standard sql
body: <p>I'm working in an R ipython notebook (relative R newbie) and trying to extract data from Google Big Query using 'bigrquery'. I'm told this should be simple, but extracting using standard sql isn't working.</p>
  
  <p>Here's my code:</p>
  
  <pre><code>require("bigrquery")
  
  # Use your project ID here
  project &lt;- "project-id" # put your project ID here
  
  standard_sql &lt;- "SELECT year, month, day, weight_pounds FROM `publicdata.samples.natality` LIMIT 5"
  
  legacy_sql &lt;- "SELECT year, month, day, weight_pounds FROM [publicdata:samples.natality] LIMIT 5"
  
  # doesn't work
  standard_data &lt;- query_exec(standard_sql, project = project, useLegacySql = FALSE)
  
  # works
  legacy_data &lt;- query_exec(legacy_sql, project = project, useLegacySql = TRUE)
  </code></pre>
  
  <p>For the standard sql above it returns the following error:</p>
  
  <pre><code>Error: Invalid table name: `publicdata:samples.natality`
  Traceback:
  
  1. query_exec(standard_sql, project = project, useLegacySql = FALSE)
  2. run_query_job(query = query, project = project, destination_table = destination_table, 
   .     default_dataset = default_dataset, create_disposition = create_disposition, 
   .     write_disposition = write_disposition, use_legacy_sql = use_legacy_sql, 
   .     quiet = quiet, ...)
  3. wait_for(job, quiet = quiet)
  4. stop(err$message, call. = FALSE)
  </code></pre>
  
  <p>It's suggesting that I've not entered the table name correctly for standard SQL, but I seemingly have and the query runs fine from the GBQ console.</p>
  
  <p>What's going wrong?</p>