Implement Mail feature in user account functionality

[mohitkh7]

Mail feature should be implemented in user account. A mail should be send to registered mail id of user on following events -

1. Account Creation
2. Forgot Password Request
3. On Changing Password

[imskr]

I would like to work on this

[mohitkh7]

Assigned to @imskr

[mohitkh7]

fixed in #31