Merge pull request #378 from roottool/change-from-open-to-io.open#377

Changed from open() to io.open()
diff --git a/pre_commit_hooks/check_yaml.py b/pre_commit_hooks/check_yaml.py
index c8665aa..5b66485 100644
--- a/pre_commit_hooks/check_yaml.py
+++ b/pre_commit_hooks/check_yaml.py
@@ -2,6 +2,7 @@
 
 import argparse
 import collections
+import io
 import sys
 from typing import Any
 from typing import Generator
@@ -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)