add featue of uploading (create/update) app from ZAT

:koala: :+1: 

You can create app through `zat create`
You can update app through `zat update`

`app_id`, `subdomain`, and `username` (email) are cached in `.zatcache`
`password` is asked every time
`password` is not displayed while typing, using 'io/console'
requests are made using `faraday`
worker statuses are queried and displayed

#### Follow up fix/feature

* [x] clear cache
* [x] find app id for existing apps
* [x] add specs
* [x] allow specifying a particular zip file to upload
* [x] allow entering full url
* [x] fix spec with webmock
* [x] simplify code (get better score on codeclimate)
* [ ] ~~add support for api token~~