minor: Change encoding to UTF-8 in open() calls.

open() calls were failing on Windows raising a UnicodeDecodeError error
since some files contained Unicode characters.

This commit fixes that and makes zulint to run on Windows.

Author: ganpa3

zulint/custom_rules.py

@@ -51,7 +51,7 @@ def __init__(
 
     def get_line_info_from_file(self, fn: str) -> List[LineTup]:
         line_tups = []
-        with open(fn) as f:
+        with open(fn, encoding='utf8') as f:
             for i, line in enumerate(f):
                 line_newline_stripped = line.strip('\n')
                 line_fully_stripped = line_newline_stripped.strip()

zulint/lister.py

@@ -17,7 +17,7 @@ def get_ftype(fpath: str, use_shebang: bool) -> str:
         return ext[1:]
     elif use_shebang:
         # opening a file may throw an OSError
-        with open(fpath) as f:
+        with open(fpath, encoding='utf8') as f:
             first_line = f.readline()
             if re.search(r'^#!.*\bpython', first_line):
                 return 'py'