Add test for checking if send_to_discord is in main

tests/test_main.py

@@ -0,0 +1,8 @@
+from discord_reminder_bot import main
+
+
+def test_if_send_to_discord_is_in_main():
+    """
+    send_to_discords needs to be in main for this program to work.
+    """
+    assert hasattr(main, "send_to_discord")