Heroku: Upgrade to Cedar-14

[shidhincr]

Currently the Codeship builds are failing because we use the old cedar in Heroku.

remote: Building source:

remote: 
remote: !   Cedar-10 is deprecated. Please update to Cedar-14:
https://devcenter.heroku.com/articles/cedar-14-migration

remote: 
To git@heroku.com:lookaround.git
! [remote rejected] b9214c5c9d0229aa49aa6efaa58c0c010053336d -> master (pre-receive hook declined)
error: failed to push some refs to 'git@heroku.com:lookaround.git'