Change stdout codec to utf-8 for h2spec

Author: masaori335

tests/gold_tests/h2/h2spec.test.py

@@ -17,6 +17,10 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 
+import sys
+import io
+sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8')
+
 Test.Summary = '''
 Test HTTP/2 with httpspec
 '''