Update app.py

app.py

@@ -385,7 +385,7 @@ async def dataframe_test(ctx):
         worksheet = gspread_bot.open("levelbot").sheet1
         test_worksheet = gspread_bot.open("test").sheet1
         
-        df = get_as_dataframe(worksheet, dtype={‘a’: np.int64})
+        df = get_as_dataframe(worksheet, dtype={'a': np.int64})
         set_with_dataframe(test_worksheet, df)