Merge pull request wp-cli#11 from wp-cli/use-trusty

Use `dist: precise` for PHP 5.3, `dist: trusty` for everything else

Merge pull request wp-cli#6 from wp-cli/clarify-bundled

Clarify this command as a bundled command

Merge pull request wp-cli#5 from 1naveengiri/Fix-multi-uninstall

Fix multi lang uninstall

Run Travis tests against dev branch