Remove obsolete imports from tests

Author: Pyry Kovanen

pandas/tests/io/json/test_json_table_schema.py

@@ -1,6 +1,5 @@
 """Tests for Table Schema integration."""
 import json
-import io
 from collections import OrderedDict
 
 import numpy as np
@@ -13,7 +12,6 @@
 from pandas.io.json.table_schema import (
     as_json_table_type,
     build_table_schema,
-    parse_table_schema,
     convert_pandas_type_to_json_field,
     convert_json_field_to_pandas_type,
     set_default_names)