BigQueryClient.sql doesn't work, has no method _get_schema_using_query

[tsdlovell]

In [3]: type(client)
Out[3]: ibis.bigquery.client.BigQueryClient

In [4]: expr = client.sql('select count(*) from raw')
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-4-59eb21b118d6> in <module>()
----> 1 expr = client.sql('select count(*) from raw')

<elided-path>/lib/python3.5/site-packages/ibis/client.py in sql(self, query)
    160         # there is already a limit in the query, we find and remove it
    161         limited_query = 'SELECT * FROM ({}) t0 LIMIT 0'.format(query)
--> 162         schema = self._get_schema_using_query(limited_query)
    163
    164         node = ops.SQLQueryResult(query, schema, self)

AttributeError: 'BigQueryClient' object has no attribute '_get_schema_using_query'