Install `Uchiwa`, a dashboard for `Sensu`

- Add dependency on `Uchiwa` cookbook.
- Install `Uchiwa`, a dashboard for `Sensu`.
- Modify the port number to link to `uchiwa`, instead of `sensu-dashboard`.
- Delete the unnecessary `sensu-dashboard` configuration.
- Delete the `monit` configuration file for `sensu-dashboard`.
- Deploy the `monit` configuration file for `uchiwa`.
Merge pull request #131 from kazu634/sensu-uchiwa-support

Support `Uchiwa` for `Sensu` dashboard.