Run Docker image with influx user

__Proposal:__
Currently, the docker image runs as a **root** user, this causes issues in a production environment where the policies do not allow the image to run as root. Since `v2.0` has been released, having the option to run the image with `influx` user would be a great option, especially on Kubernetes with PSP enabled.

__Current behavior:__
The image runs with `nobody` user with volume at `/.influxdb`

__Desired behavior:__
Run the image with `influx` user, with volume owned by this user.

__Alternatives considered:__
NA

__Use case:__
Most production setup especially on Kubernetes runs with restricted access to the docker image for security reasons. Being that `v2.0` has been released, this makes the perfect opportunity to release the images which will conform with the security policies for various organizations to use the platform.