* fix(Api): do not infer project root from script location
* fix(builders): do not infer project root from script location
* fix(target): do not infer project root from script location
* test(e2e): cleanup and extend E2E tests
- Renames the file with the only existing E2E test
- Makes existing test use the API instance returned by
`Api.createPlatform`
- Adds another test that ensures we can still require the API from
`platformProjectPath/cordova/Api.js`
* fix(check_reqs): do not infer project root from script location
* refactor: unify installation on devices & emulators
This change replaces the almost identical methods `device.install` and
`emulator.install` with the generic `target.install`.
* fix: use unified installation in platform-centric bins
