Authentication: Login/Register

[Austin2Shih]

• [x] create in typeDefs, resolvers, and services Authentication as if Authentication was a data model.
• [x] Create Login and Register mutations.
• [x] Make sure both of these upon success are able to set "auth_token" in cookies with the JWT token. Make sure the cookie is samesite: true, secure, httponly.
• Your login mutation should take in an email and password, check if the user exists and compare the password hashes.
• Your register mutation should take in email and password, check if the user exists and fail if they do exist. If not then hash the password and store it.