Let Aphlict listen on the specified host

Summary: We allow user to specify the host to listen to but we listen on 127.0.0.1 instead.

Test Plan:
Hardcoded the path and verified that I can connect to the host from other machine.

Verified that localhost still doesn't allow remote connections.

Reviewers: ddfisher, epriestley, nh

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D4238