Log Message:
Update to 2.0.0

Upstream changes:
2.0.0 2013-11-06 09:15:00+0900
    [BUG FIXES]
    - Merged the pull-request #13, which fixed an issue where
      the behavior of role method confliction was different
      from Moose. This change might affect your existing code
      so the major version has incremented.
      See t/030_roles/role_conflict_and_inheritance.t for details.