diff --git a/.travis.yml b/.travis.yml
index 9f422c6..8d17484 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,13 +1,11 @@
 language: python
+
+python:
+  - "2.7"
+  - "3.6"
+  - "3.7-dev" # 3.7 development branch
+
 install:
   - python setup.py develop
-  - pip install tox
-script: tox -e $TOXENV
 notifications:
   email: false
-env:
-  - TOXENV=py27
-  - TOXENV=py33
-  - TOXENV=py34
-  - TOXENV=nightly
-  - TOXENV=pypy
diff --git a/bigquery/client.py b/bigquery/client.py
index 17a3a89..bd4a700 100644
--- a/bigquery/client.py
+++ b/bigquery/client.py
@@ -15,6 +15,9 @@
 from googleapiclient.errors import HttpError
 from httplib2 import Http
 
+if sys.version_info >= (3, 0):
+    basestring = str
+
 BIGQUERY_SCOPE = [
     'https://www.googleapis.com/auth/bigquery'
 ]
@@ -1213,7 +1216,7 @@ def wait_for_job(self, job, interval=5, timeout=60):
                                                jobId=job_id)
             job_resource = request.execute()
             self._raise_executing_exception_if_error(job_resource)
-            complete = job_resource.get('status').get('state') == u'DONE'
+            complete = job_resource.get('status').get('state') == 'DONE'
             elapsed_time = time() - start_time
 
         # raise exceptions if timeout
@@ -1489,7 +1492,7 @@ def _filter_tables_by_time(self, tables, start_time, end_time):
             Table names that are inside the time range
         """
 
-        return [table_name for (table_name, unix_seconds) in tables.items()
+        return [table_name for (table_name, unix_seconds) in list(tables.items())
                 if self._in_range(start_time, end_time, unix_seconds)]
 
     def _in_range(self, start_time, end_time, time):
diff --git a/bigquery/query_builder.py b/bigquery/query_builder.py
index 1054299..b28c1d9 100644
--- a/bigquery/query_builder.py
+++ b/bigquery/query_builder.py
@@ -81,7 +81,7 @@ def _render_select(selections):
         return 'SELECT *'
 
     rendered_selections = []
-    for name, options in selections.items():
+    for name, options in list(selections.items()):
         if not isinstance(options, list):
             options = [options]
 
diff --git a/bigquery/tests/test_client.py b/bigquery/tests/test_client.py
index 1315147..bfbe800 100644
--- a/bigquery/tests/test_client.py
+++ b/bigquery/tests/test_client.py
@@ -655,9 +655,9 @@ def setUp(self):
     def test_completed_jobs(self):
         """Ensure we can detect completed jobs"""
 
-        return_values = [{'status': {'state': u'RUNNING'},
+        return_values = [{'status': {'state': 'RUNNING'},
                           'jobReference': {'jobId': "testJob"}},
-                         {'status': {'state': u'DONE'},
+                         {'status': {'state': 'DONE'},
                           'jobReference': {'jobId': "testJob"}}]
 
         def side_effect(*args, **kwargs):
@@ -667,7 +667,7 @@ def side_effect(*args, **kwargs):
 
         job_resource = self.client.wait_for_job(
             {'jobReference': {'jobId': "testJob"},
-             'status': {'state': u'RUNNING'}},
+             'status': {'state': 'RUNNING'}},
             interval=.01,
             timeout=.05)
 
@@ -676,7 +676,7 @@ def side_effect(*args, **kwargs):
 
     def test_timeout_error(self):
         """Ensure that timeout raise exceptions"""
-        incomplete_job = {'status': {'state': u'RUNNING'},
+        incomplete_job = {'status': {'state': 'RUNNING'},
                           'jobReference': {'jobId': "testJob"}}
 
         self.api_mock.jobs().get().execute.return_value = incomplete_job
@@ -685,7 +685,7 @@ def test_timeout_error(self):
 
     def test_wait_job_http_error(self):
         """ Test wait job with http error"""
-        job = {'status': {'state': u'RUNNING'},
+        job = {'status': {'state': 'RUNNING'},
                'jobReference': {'jobId': "testJob"}}
 
         expected_result = {
@@ -709,7 +709,7 @@ def test_wait_job_http_error(self):
 
     def test_wait_job_error_result(self):
         """ Test wait job with error result"""
-        job = {'status': {'state': u'RUNNING'},
+        job = {'status': {'state': 'RUNNING'},
                'jobReference': {'jobId': "testJob"}}
 
         expected_result = {
@@ -733,9 +733,9 @@ def test_wait_job_error_result(self):
     def test_accepts_job_id(self):
         """Ensure it accepts a job Id rather than a full job resource"""
 
-        return_values = [{'status': {'state': u'RUNNING'},
+        return_values = [{'status': {'state': 'RUNNING'},
                           'jobReference': {'jobId': "testJob"}},
-                         {'status': {'state': u'DONE'},
+                         {'status': {'state': 'DONE'},
                           'jobReference': {'jobId': "testJob"}}]
 
         def side_effect(*args, **kwargs):
@@ -751,9 +751,9 @@ def side_effect(*args, **kwargs):
         self.assertIsInstance(job_resource, dict)
 
     def test_accepts_integer_job_id(self):
-        return_values = [{'status': {'state': u'RUNNING'},
+        return_values = [{'status': {'state': 'RUNNING'},
                           'jobReference': {'jobId': "testJob"}},
-                         {'status': {'state': u'DONE'},
+                         {'status': {'state': 'DONE'},
                           'jobReference': {'jobId': "testJob"}}]
 
         def side_effect(*args, **kwargs):
@@ -784,7 +784,7 @@ def setUp(self):
 
     def test_csv_job_body_constructed_correctly(self):
         expected_result = {
-            'status': {'state': u'RUNNING'},
+            'status': {'state': 'RUNNING'},
         }
 
         body = {
@@ -843,7 +843,7 @@ def test_csv_job_body_constructed_correctly(self):
 
     def test_json_job_body_constructed_correctly(self):
         expected_result = {
-            'status': {'state': u'RUNNING'},
+            'status': {'state': 'RUNNING'},
         }
 
         body = {
@@ -938,7 +938,7 @@ def test_skip_leading_rows_exception_if_not_csv(self):
     def test_accepts_single_source_uri(self):
         """Ensure that a source_uri accepts a non-list"""
         expected_result = {
-            'status': {'state': u'RUNNING'},
+            'status': {'state': 'RUNNING'},
         }
 
         body = {
@@ -1033,7 +1033,7 @@ def setUp(self):
     def test_export(self, mock_generate_hex):
         """ Ensure that export is working in normal circumstances """
         expected_result = {
-            'status': {'state': u'RUNNING'},
+            'status': {'state': 'RUNNING'},
         }
 
         body = {
@@ -1134,7 +1134,7 @@ def setUp(self):
     def test_write(self):
         """ Ensure that write is working in normal circumstances."""
         expected_result = {
-            'status': {'state': u'RUNNING'},
+            'status': {'state': 'RUNNING'},
         }
 
         body = {
@@ -1175,7 +1175,7 @@ def test_write(self):
     def test_write_maxbilltier(self):
         """ Ensure that write is working when maximumBillingTier is set"""
         expected_result = {
-            'status': {'state': u'RUNNING'},
+            'status': {'state': 'RUNNING'},
         }
 
         body = {
diff --git a/bigquery/tests/test_schema_builder.py b/bigquery/tests/test_schema_builder.py
index 060162b..80023d4 100644
--- a/bigquery/tests/test_schema_builder.py
+++ b/bigquery/tests/test_schema_builder.py
@@ -15,7 +15,7 @@ def test_str_is_string(self):
         six.assertCountEqual(self, bigquery_type("Bob"), 'string')
 
     def test_unicode_is_string(self):
-        six.assertCountEqual(self, bigquery_type(u"Here is a happy face \u263A"),
+        six.assertCountEqual(self, bigquery_type("Here is a happy face \u263A"),
                              'string')
 
     def test_int_is_integer(self):