address bflad/chef-docker #137 and support that trusty tahr.
add helper bool to determine default ubuntu package repo
refactor to use new helper ubuntu/docker ppa boolean
modify upstart spec to match upstart template
for once rubocop, i completely agree with you
Merge pull request #138 from brandonmartin/support_trusty_tahr

address bflad/chef-docker #137 and support that trusty tahr.