Bigquery Write with schema None: TypeError: 'NoneType' object has no attribute '__getitem__'

input_data = [
   {'str': 'test'}
 ]
(pipeline | 'create' >> beam.Create(input_data)
   | 'write' >> beam.io.WriteToBigQuery(
   '<project-id>:beam_test.test'))

WARNING:root:Start running in the cloud
Traceback (most recent call last):
 File "test_pipeline.py", line 193, in <module>
 main()
 File "test_pipeline.py", line 183, in main
 '<project-id>:beam_test.test'))
 File "/mnt/c/Users/Juta/Documents/02-projects/apache/beam/sdks/venv2/local/lib/python2.7/site-packages/apache_beam/pvalue.py", line 112, in __or__
 return self.pipeline.apply(ptransform, self)
 File "/mnt/c/Users/Juta/Documents/02-projects/apache/beam/sdks/venv2/local/lib/python2.7/site-packages/apache_beam/pipeline.py", line 470, in apply
 label or transform.label)
 File "/mnt/c/Users/Juta/Documents/02-projects/apache/beam/sdks/venv2/local/lib/python2.7/site-packages/apache_beam/pipeline.py", line 480, in apply
 return self.apply(transform, pvalueish)
 File "/mnt/c/Users/Juta/Documents/02-projects/apache/beam/sdks/venv2/local/lib/python2.7/site-packages/apache_beam/pipeline.py", line 516, in apply
 pvalueish_result = self.runner.apply(transform, pvalueish, self._options)
 File "/mnt/c/Users/Juta/Documents/02-projects/apache/beam/sdks/venv2/local/lib/python2.7/site-packages/apache_beam/runners/runner.py", line 193, in apply
 return m(transform, input, options)
 File "/mnt/c/Users/Juta/Documents/02-projects/apache/beam/sdks/venv2/local/lib/python2.7/site-packages/apache_beam/runners/dataflow/dataflow_runner.py", line 617, in apply_WriteToBigQuery
 parse_table_schema_from_json(json.dumps(transform.schema)),
 File "/mnt/c/Users/Juta/Documents/02-projects/apache/beam/sdks/venv2/local/lib/python2.7/site-packages/apache_beam/io/gcp/bigquery_tools.py", line 130, in parse_table_schema_from_json
 fields = [_parse_schema_field(f) for f in json_schema['fields']]
TypeError: 'NoneType' object has no attribute '__getitem__'