Ignore Errors when reading Files

Workaround for german umelts and similar reading utf-8 issues

yamllint/cli.py

@@ -202,7 +202,7 @@ def run(argv=None):
     for file in find_files_recursively(args.files, conf):
         filepath = file[2:] if file.startswith('./') else file
         try:
-            with io.open(file, newline='') as f:
+            with io.open(file, newline='', errors='ignore') as f:
                 problems = linter.run(f, conf, filepath)
         except EnvironmentError as e:
             print(e, file=sys.stderr)