Ajax Validations on Signup and Login

[ashutoshkrris]

Resolves : #162 I have added AJAX Validations on Email and Password Fields. The following things is being done:

1. On signup and login page, email is validated against a regex pattern.
2. On signup page, email is checked if it already exists in the database i.e. if user is already registered.
3. On signup page, password is validated against a regex pattern.
4. On login page, email is checked if the email doesn't exist in the database i.e. if user is not registered.

I have attached a demo video for it.

https://user-images.githubusercontent.com/47353498/114277662-b8e15f80-9a49-11eb-86c7-94eb3d4d5c2b.mp4