chore(build): Set Firebase, Angular, and rxjs as peerDependencies

[davideast]

Checklist

• Issue number for this PR: Duplicate Identifier Errors #707, Property 'map' does not exist on type 'AngularFireAuth' #747
• Docs included?: yes
• Test units included?: N/A
• e2e tests included?: N/A
• In a clean directory, npm install, npm run build, and npm test run successfully? yes

Description

In post build all dependencies (Firebase, Angular, rxjs) are set as peerDeependencies to avoid version mismatch errors.