Changed maintainer, fixed changelog and added watch file

After discussion with Thibault Cohen, I will be maintaining this package with his help.

I have opened an ITP: https://bugs.debian.org/764643

I am currently uploading this version of the package (with maintainer changed) for review.

We have until the end of october to be accepted in the next debian release. This is what we are aiming for.

Update: Package was uploaded [here](https://mentors.debian.net/package/influxdb-python)