Create log directory if it does not exist

Summary: Create log directory if it does not exist. In particular, I want to check log.access.path if it does not exist.

Test Plan: Saw the log directory created.

Reviewers: epriestley, Blessed Reviewers

Reviewed By: epriestley, Blessed Reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11729