Updated .arcconfig to match newer style configuration.

Summary: If I'm not mistaken, project_id was recently replaced by project.name and conduit_uri replaced by phabricator.uri.

Test Plan: I guess if this differential works, then everything is okay.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D8334