Template for email added (email/verification_expiry_email)
The management command filters the SoftwareSecurePhotoVerification model on the basis of following criteria :
-- the verification is approved
-- the start_date < expiry_date < today or specified days have passed to resend email
After the basic filtering batches are created to send email. For each verification in a batch email is sent and
email_expiry_date is set to 15 days from today (default days are 15, it can be changed too)
Between each batch there is a delay of sleep_time seconds
