Fixes an regression issue with line/column number calculations (resolves

 #218)

slither/slither.py

@@ -65,7 +65,7 @@ def __init__(self, contract, **kwargs):
             for path, ast in cryticCompile.asts.items():
 
                 self._parse_contracts_from_loaded_json(ast, path)
-                with open(path) as f:
+                with open(path, encoding='utf8', newline='') as f:
                     self.source_code[path] = f.read()
 
         self._detectors = []