Changed from open() to io.open()

pre_commit_hooks/check_yaml.py

diff --git a/pre_commit_hooks/check_yaml.py b/pre_commit_hooks/check_yaml.py
index c8665aa..9bbd36c 100644
--- a/pre_commit_hooks/check_yaml.py
+++ b/pre_commit_hooks/check_yaml.py
@@ -3,6 +3,7 @@
 import argparse
 import collections
 import sys
+import io
 from typing import Any
 from typing import Generator
 from typing import Optional
@@ -58,7 +59,7 @@
     retval = 0
     for filename in args.filenames:
         try:
-            with open(filename) as f:
+            with io.open(filename, encoding='UTF-8') as f:
                 load_fn(f)
         except ruamel.yaml.YAMLError as exc:
             print(exc)