Write integration test for init

[jsjoeio]

Summary

Integration test for the init command

Basic example

The test asserts that:

• the init command works without a flag
• the init command works with a flag of a valid project
• the init command displays an error when you pass an invalid flag
• the init command installs eb-scripts and adds a script to the package.json

Motivation

Testing is important! We want to be able to ship code confidently :)

[jsjoeio]

Helpful resources:

• https://github.com/mcavaliere/BYOBoilerplate
• https://github.com/ember-cli/ember-cli/blob/master/tests/integration/models/blueprint-test.js#L265-L291