go vet
drop/omit
some installations of ubuntu 13.04 (digital ocean Ubuntu 13.04 x64 Server in this case) require software-properties-common to be installed before being able to use add-apt-repository
linted names
Merge pull request #802 from johncosta/ubuntu-1304-add-apt-repository

- Documentation: adding missing dependency to the ubuntu linux install page.
Remove provider specifc language
Merge pull request #808 from dotcloud/795-lintify

Cleanup source
Put back panic for go1.0.3 compatibility
Merge pull request #818 from johncosta/ubuntu-1304-add-apt-repository

Remove provider specifc language