Bring back net-mgmt/py-pdagent-integrations & net-mgmt/py-pdagent

NOTE: net-mgmt/py-pdagent-integrations was previously
      net-mgmt/pdagent-integrations

The PagerDuty Agent is a program that lets you easily integrate your
monitoring system with PagerDuty.

WWW: https://github.com/PagerDuty/pdagent