Subscription management

Your task is to create a server that exposes an API to manage subscriptions, creating, checking their status etc.

Description

Your server should expose an API via either REST or graphql.

The API should support:

creating a new subscription for a msisdn with an activate_at date and a type;
- if a non-cancelled subscription already has the same msisdn the request should be rejected;
fetching information about a subscription, which should show:
- all of the subscription's data,
- as well as which operator owns the subscription (using the API provided by PTS;
changing the activation date of a pending subscription;
pausing and reactivating the subscription;
cancelling the subscription.

A subscription represents a user's phone subscription, which has the following information:

msisdn which is the subscription's number;
activate_at which is the date when the subscription is activated in the system;
type which is either PBX or CELL;
status which is one of pending, activated, paused or cancelled.

You should submit your code by using git bundle and sending the bundled file via mail.

* Your work will not be used in the Telness product or in any part of such product, the only purpose is to test your technical skills.

Your submission should include a README.md file documenting how to install start and test the project;
You won't have the time to make everything perfect, just document what is lacking and how you would improve it;
Do not make the task harder than it is, it should take a couple of hours but absolutely not more than 8 hours;
You are free to use any technology and framework of your choice.