erchef 1.2.25

Updated deps:

  chef_objects
    2013-09-12 63aeadd Refactor eunit tests for verifying s3 url config is respected
    2013-09-12 069b656 Added testing for host_header and s3_external_url
    2013-09-09 3e1cb0e CHEF-4086: Use s3_external_url configuration for generating artifact URLs for clients