How to set timezone

[setchy]

I am using https://github.com/ruimarinho/docker-openvpn-monitor to display openvpn connection metrics.

The Up Since metric currently shows the datetime in UTC, which is the timezone that docker-openvpn-client is configured with.

I've tried setting

environment:
  - TZ=America/New_York

but it doesnt appear to have any influence on docker-openvpn-client

[setchy]

Looks like in order for this to work, the tzdata package needs to be added (reference)

[setchy]

#92