Removed debian packaging from upstream

The debian folder was a great incentive to get someone started with the Debian packaging, but now that it's done, there is no reason to keep it upstream. It will most likely end up outdated (it already is).

The Debian packaging is hosted on a git repo by the Debian project here: http://anonscm.debian.org/cgit/collab-maint/influxdb-python.git

Reminder: the qa page is [here](https://packages.qa.debian.org/i/influxdb-python.html). The package should make it to testing in 5 days.