pi-hole/PADD v3.7.0 on GitHub

What's Changed

biggest change: we switched from bash to sh and made the script more POSIX compliant. This should allow to run it on even more OS (by @yubiuser in #212)
we removed the padd.pid file (by @yubiuser in #197)
we get Pi-hole's status now by directly communicating with FTL's API endpoint without invoking the pihole script (@yubiuser in #209)
we communicate with FTL now via netcat which made the code much more readable and in line with the documentation (by @yubiuser in #210)
instead of creating the piHoleVersion file in the directory where the script is located, we now create it in /tmp to prevent permission issues (by @yubiuser in #211)

Full Changelog: v3.6.7...v3.7.0