Future<void> _getUserDoc() async {
    final FirebaseAuth _auth = FirebaseAuth.instance;
    final Firestore _firestore = Firestore.instance;

    FirebaseUser user = await _auth.currentUser();
    setState(() {
      userRef = _firestore.collection('users').document(user.uid);
    });
  }

USERS
-user1 (current user)
-name: John
-age: 20
--FRIENDS
----user2id
----user3id

-user2
-name: Richie
-age: 20
--FRIENDS
----user3id

Padding(
                    padding:
                        const EdgeInsets.only(left: 20.0, right: 20.0, top: 10.0),
                    child: Text(
                      'Richie',
                      style: TextStyle(
                          fontFamily: 'Montserrat',
                          fontWeight: FontWeight.bold,
                          fontSize: 17.0),
                    ),
                  ),