fix(stepper): console error in development mode

[vagnersabadi]

Problem

When adding the stepper component in a modal, the error below is displayed on the browser console in development mode.

Solution

ChangeDetectorRef was added to detect changes in the component and no longer show the error

Step by step to reproduce

1. Create a modal
2. Import the component stepper to the modal

Solution taken from here

https://github.com/gbrlsnchs/material2-carousel/issues/8