Rocketeer 0.5.0

- [x] Fix weird behavior with credentials
- [x] **Add a `deploy:update` task that updates the remote server without doing a new release**
- [x] **Add a `deploy:test` to run the tests on the server**
- [x] The `deploy:check` command now checks PHP extensions for the cache/database/session drivers you set
- [x] Rocketeer now share logs by default between releases
- [x] Added a `$silent` flag to make a `Task::run` call silent no matter what