Be nice to the libraries

What's Changed

• Change scan interval to every 4 hours instead of every 10 minutes by @PTST in #17

Full Changelog: v0.1.7...v0.1.8

After some correspondence with a nice employee at Rudersdal Library who where concerned that this integration was requesting them so much that they thought at first that it might be a DDOS attempt, i have turned down the polling frequency a fair bit.
And I mean, fair enough, we probably don't need real-time data about our reservations 😄