python-bigquery-sqlalchemy: Problem with SQLAlchemy 1.4.0

Hello,

New version of SQLAlchemy (1.4.0) was released 15.03.2020 and since then I got following error:

 File "/layers/google.python.pip/pip/lib/python3.8/site-packages/promise/promise.py", line 489, in _resolve_from_executor
    executor(resolve, reject)
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/promise/promise.py", line 756, in executor
    return resolve(f(*args, **kwargs))
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/graphql/execution/middleware.py", line 75, in make_it_promise
    return next(*args, **kwargs)
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/graphene_sqlalchemy/fields.py", line 78, in connection_resolver
    return on_resolve(resolved)
  File "src/adtrender_api/connections.py", line 52, in resolve_connection
    return super().resolve_connection(connection_type, model, info, args, resolved)
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/graphene_sqlalchemy/fields.py", line 53, in resolve_connection
    _len = resolved.count()
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/sqlalchemy/orm/query.py", line 3009, in count
    return self._from_self(col).scalar()
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/sqlalchemy/orm/query.py", line 2753, in scalar
    ret = self.one()
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/sqlalchemy/orm/query.py", line 2730, in one
    return self._iter().one()
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/sqlalchemy/orm/query.py", line 2768, in _iter
    result = self.session.execute(
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/sqlalchemy/orm/session.py", line 1653, in execute
    result = conn._execute_20(statement, params or {}, execution_options)
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/sqlalchemy/engine/base.py", line 1520, in _execute_20
    return meth(self, args_10style, kwargs_10style, execution_options)
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/sqlalchemy/sql/elements.py", line 313, in _execute_on_connection
    return connection._execute_clauseelement(
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/sqlalchemy/engine/base.py", line 1381, in _execute_clauseelement
    compiled_sql, extracted_params, cache_hit = elem._compile_w_cache(
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/sqlalchemy/sql/elements.py", line 533, in _compile_w_cache
    compiled_sql = self._compiler(
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/sqlalchemy/sql/elements.py", line 566, in _compiler
    return dialect.statement_compiler(dialect, self, **kw)
  File "/layers/google.python.pip/pip/lib/python3.8/site-packages/pybigquery/sqlalchemy_bigquery.py", line 137, in __init__
    super(BigQueryCompiler, self).__init__(dialect, statement, column_keys, inline, **kwargs)
TypeError: __init__() got multiple values for argument 'cache_key'" 

I rolled back to SQLAlchemy==1.3.20 and it works fine.