Setup Auth flow

[Arjun-G-04]

Objective

Make clean, elegant UI following Google's Material Design standards for pages involved in authentication. Make use of React Native Paper library (link in README) and Material Design docs. Minimum login and register page required. Consider Google and DAuth is also present for authentication.

Guidelines

• Follow https://github.com/greaterThan75/ams-frontend/issues/2 guidelines.
• Code simple, neat UI for the required page.
• UI should be mobile first. Desktop design can be improved later.