Update Login API to provide refresh token

[adarsh-a-tw]

As a user, I should receive a refresh token, so that I can use it to obtain access tokens.

[adarsh-a-tw]

Tech Tasks:

• Update login API to provide access & refresh token pair
• Access token expiry to be set at 10 mins and refresh token expiry to 1 day

[aswath-s-tw]

LGTM !