Feat: login and signup with Firebase

[huongphamx]

This Project using Firebase for easily integrate Authentication, and ready-to-use Google Analytics

• Login by email and password, or social auth with Google and Facebook
• Sign up: similar, with email and password, or with social auth

[huongphamx]

Todo:

• [x] setup Firebase
• [x] setup vee-validate
• [x] signup: add modal
• [ ] signup: for email signup, add signup form with email, password, confirm password fields, validate form and submit calling Firebase
• [ ] signup: for social signup, add 2 button - Facebook and Google, with handler calling Firebase
• [x] login: add modal
• [ ] login: for email login, add signup form with email, password, validate form and submit calling Firebase
• [ ] login: for social login, add 2 button - Facebook and Google, with handler calling Firebase