Support for OpsGenie in EU region

[guxlightyear]

OpsGenie uses different domains for Europe (api.eu.opsgenie.com) than the rest of the world (api.opsgenie.com). See https://docs.opsgenie.com/docs/alert-api

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If using the EU instance of Opsgenie, the URL needs to be https://api.eu.opsgenie.com for requests to be successful.

Unfortunately this means that for EU users opsgenie-cli is not a viable option currently.

A possible option would be to make the domain name configurable via argument? Something like:

$ opsgenie alerts --query=<your query> --domain=api.eu.opsgenie.com