Install React Native Elements UI library

[dbelokon]

Issue This PR Addresses

Fixes #2730

Type of Change

• Bugfix: Change which fixes an issue
• New Feature: Change which adds functionality
• Documentation Update: Change which improves documentation
• UI: Change which improves UI
• Dependency: Change that adds updates dependency list

Description

This PR adds react-native-elements, version 3.4.2. Version 4.0.0 is in its beta, so it is not available yet through the npm registry.

Steps to test the PR

1. If you don't have it, add my repo in your remote list: git remote add dbelokon https://github.com/dbelokon/telescope.git.
2. Fetch my changes: git fetch dbelokon
3. Track my changes: git checkout issue-2730 (this will create a local branch that points to my remote branch!)
4. Go to src/mobile.
5. npm install
6. Try out the elements to your heart's content!

Checklist

• Quality: This PR builds and passes our npm test and works locally
• Tests: This PR does not include tests because it does not add new features.
• Screenshots: This PR does not include screenshots because no UI changes are done.
• Documentation: This PR does not add docs because there are no features to implement

[gitpod-io]

[Kevan-Y]

LGTM

[AmasiaNalbandian]

I merged it in so we can start moving along other stuff for RN. Thanks so much for doing this great work everyone and @dbelokon for making the PR.