Refactor: add typing in exceptions.py

Author: starcat37

Diff for: pymysqlreplication/exceptions.py

@@ -1,19 +1,19 @@
 class TableMetadataUnavailableError(Exception):
-    def __init__(self, table):
+    def __init__(self, table: str) -> None:
         Exception.__init__(self,"Unable to find metadata for table {0}".format(table))
 
 
 class BinLogNotEnabled(Exception):
-    def __init__(self):
+    def __init__(self) -> None:
         Exception.__init__(self, "MySQL binary logging is not enabled.")
 
 
 class StatusVariableMismatch(Exception):
-    def __init__(self):
-        Exception.__init__(self, " ".join(
+    def __init__(self) -> None:
+        Exception.__init__(self, " ".join([
             "Unknown status variable in query event."
             , "Possible parse failure in preceding fields"
             , "or outdated constants.STATUS_VAR_KEY"
             , "Refer to MySQL documentation/source code"
             , "or create an issue on GitHub"
-        ))
+        ]))