Subscribing with a docket identifier multiple times results in multiple SMS reminders sent out to the subscriber

[NathanWEdwards]

The application sends out one SMS message as a reminder when a user subscribes to a court session multiple times. When a user subscribes to multiple court sessions users are receiving multiple texts.

Steps to recreate the issue:

1. Select a docket number.
2. Text the docket identifier to (802) 760 2922.
3. Confirm ‘yes’ to receive a notification for the upcoming court date.
4. Text the docket identifier, again, to (802) 760 2922.
5. Confirm ‘yes’, again, to receive a notification for the upcoming court date.

As a user when I subscribe to the same court session multiple times I want to receive one text reminder.

Given a user has subscribed to the same court date multiple times,
When the application sends out a reminder to the user,
Then only one SMS notification should be sent out to remind the user of the subscribed date.

Acceptance Criteria:
A user subscribing to a court session multiple times receives one SMS reminder of the upcoming court date.