process.exit(0) on success

some test runs may leave things running. must exit here since
cli.js must support daemon use cases (i.e. start, docs).

see yahoo/mojito-cli@b133ae1b72d362f35c32b7a21ceadf75ef7e39ab
v0.0.4
Merge branch 'develop' of github.com:isao/mojito-cli-test into develop