Two threads concurrently tried to get the same name: master
## Issue

### Issue description
This bug popped up on 0.13.0. Exact reproduction case TBD, though I suspect it has something to do with statements called from inside of models.

### Results
Error during parsing:
```
2019-04-01 11:33:53,380 (MainThread): Encountered an error:
2019-04-01 11:33:53,381 (MainThread): Runtime Error
  Two threads concurrently tried to get the same name: master
```

### System information
The output of `dbt --version`:
```
0.13.0
```

### Steps to reproduce
TBD
diff --git a/plugins/bigquery/dbt/adapters/bigquery/impl.py b/plugins/bigquery/dbt/adapters/bigquery/impl.py
index ad5fbf724..c36337f45 100644
--- a/plugins/bigquery/dbt/adapters/bigquery/impl.py
+++ b/plugins/bigquery/dbt/adapters/bigquery/impl.py
@@ -156,7 +156,8 @@ class BigQueryAdapter(BaseAdapter):
             )
 
         try:
-            table = self.connections.get_bq_table(database, schema, identifier)
+            table = self.connections.get_bq_table(database, schema, identifier,
+                                                  conn_name=model_name)
         except google.api_core.exceptions.NotFound:
             table = None
         return self._bq_table_to_relation(table)
diff --git a/test/unit/test_bigquery_adapter.py b/test/unit/test_bigquery_adapter.py
index b667cf38a..971c6b189 100644
--- a/test/unit/test_bigquery_adapter.py
+++ b/test/unit/test_bigquery_adapter.py
@@ -18,7 +18,7 @@ def _bq_conn():
     return conn
 
 
-class TestBigQueryAdapter(unittest.TestCase):
+class BaseTestBigQueryAdapter(unittest.TestCase):
 
     def setUp(self):
         flags.STRICT_MODE = True
@@ -73,6 +73,7 @@ class TestBigQueryAdapter(unittest.TestCase):
         return adapter
 
 
+class TestBigQueryAdapterAcquire(BaseTestBigQueryAdapter):
     @patch('dbt.adapters.bigquery.BigQueryConnectionManager.open', return_value=_bq_conn())
     def test_acquire_connection_oauth_validations(self, mock_open_connection):
         adapter = self.get_adapter('oauth')
@@ -134,6 +135,52 @@ class TestBigQueryAdapter(unittest.TestCase):
                                             location='Luna Station')
 
 
+class TestConnectionNamePassthrough(BaseTestBigQueryAdapter):
+
+    def setUp(self):
+        super(TestConnectionNamePassthrough, self).setUp()
+        self._conn_patch = patch.object(BigQueryAdapter, 'ConnectionManager')
+        self.conn_manager_cls = self._conn_patch.start()
+
+        self._relation_patch = patch.object(BigQueryAdapter, 'Relation')
+        self.relation_cls = self._relation_patch.start()
+
+        self.mock_connection_manager = self.conn_manager_cls.return_value
+        self.conn_manager_cls.TYPE = 'bigquery'
+        self.relation_cls.DEFAULTS = BigQueryRelation.DEFAULTS
+
+        self.adapter = self.get_adapter('oauth')
+
+    def tearDown(self):
+        super(TestConnectionNamePassthrough, self).tearDown()
+        self._conn_patch.stop()
+        self._relation_patch.stop()
+
+    def test_get_relation(self):
+        self.adapter.get_relation('db', 'schema', 'my_model', 'my_conn')
+        self.mock_connection_manager.get_bq_table.assert_called_once_with('db', 'schema', 'my_model', conn_name='my_conn')
+
+    def test_create_schema(self):
+        self.adapter.create_schema('db', 'schema', 'my_conn')
+        self.mock_connection_manager.create_dataset.assert_called_once_with('db', 'schema', 'my_conn')
+
+    @patch.object(BigQueryAdapter, 'check_schema_exists')
+    def test_drop_schema(self, mock_check_schema):
+        mock_check_schema.return_value = True
+        self.adapter.drop_schema('db', 'schema', 'my_conn')
+        self.mock_connection_manager.drop_dataset.assert_called_once_with('db', 'schema', 'my_conn')
+
+    def test_get_columns_in_relation(self):
+        self.mock_connection_manager.get_bq_table.side_effect = ValueError
+        self.adapter.get_columns_in_relation(
+            MagicMock(database='db', schema='schema', table_name='ident'),
+            'my_conn'
+        )
+        self.mock_connection_manager.get_bq_table.assert_called_once_with(
+            database='db', schema='schema', identifier='ident', conn_name='my_conn'
+        )
+
+
 class TestBigQueryRelation(unittest.TestCase):
     def setUp(self):
         flags.STRICT_MODE = True
['test/unit/test_bigquery_adapter.py', 'plugins/bigquery/dbt/adapters/bigquery/impl.py']