fix(subscription-service): make description non mandatory (#40)

make description non mandatory

gh-subs

## Description

Please include a summary of the change and which issue is fixed. Please
also include relevant motivation and context. List any dependencies that
are required for this change.

Fixes # (issue)

## Type of change

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- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] Intermediate change (work in progress)

## How Has This Been Tested?

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instructions so we can reproduce. Please also list any relevant details
for your test configuration

- [ ] Test A
- [ ] Test B

## Checklist:

- [ ] Performed a self-review of my own code
- [ ] npm test passes on your machine
- [ ] New tests added or existing tests modified to cover all changes
- [ ] Code conforms with the style guide
- [ ] API Documentation in code was updated
- [ ] Any dependent changes have been merged and published in downstream
modules

services/subscription-service/src/models/plan.model.ts

@@ -27,9 +27,8 @@ export class Plan extends UserModifiableEntity {
   @property({
     type: 'string',
     description: 'description of the plan',
-    required: true,
   })
-  description: string;
+  description?: string;
 
   @property({
     type: 'number',