decouple from ember-cli

- [ ] https://github.com/ember-cli/blueprint/blob/master/lib/blueprint.js#L660
- [ ] https://github.com/ember-cli/blueprint/blob/master/lib/blueprint.js#L783-L802
- [ ] provide boundary for abstract tasks `taskFor('npm-install`)` maybe rename to `node_module:install` and external consumer can provide the functionality
- [ ] load tasks via what the consumer provides: https://github.com/ember-cli/blueprint/blob/master/lib/blueprint.js#L1107
- [ ] provide standalone UI abstraction that can be provided, otherwise have ember-cli provide that UI.
- [ ] load blueprints based on provided lookup strategy:
- https://github.com/ember-cli/blueprint/blob/master/lib/blueprint.js#L1244
- https://github.com/ember-cli/blueprint/blob/master/lib/blueprint.js#L1271
- https://github.com/ember-cli/blueprint/blob/master/lib/blueprint.js#L1298

- [ ] https://github.com/ember-cli/blueprint/blob/master/lib/blueprint.js#L1479-L1480
- [ ] in-report addon stuff: https://github.com/ember-cli/blueprint/blob/master/lib/blueprint.js#L435
- [ ] references to `pod`
- [ ] references to ember-cli
- [ ] https://github.com/ember-cli/blueprint/blob/1ee765ee6adb9df8bd627f50e53c52c2ba082498/lib/blueprint.js#L27