Add Serialize and deserialize methods to NeedParams.ts

Description

Create tests for serialize and deserialize for src/drone-charging/NeedParams.ts using Jest

Related Issue

Issue #97

Motivation and Context

Increase the test coverage.

How Has This Been Tested?

using

npm run jest

Screenshots (if appropriate):

Types of changes

[ ] 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 change)
[ ] Enhancement that improves upon existing functionality

Checklist:

[x] My code follows the code style of this project.
[ ] My change requires a change to the documentation.
[ ] I have read the CONTRIBUTING document.
[x] I have added tests to cover my changes.
[ ] All new and existing tests passed.
```
~/davFoundation/dav-js$ npm run jest
```

> dav-js@0.1.19 jest /home/abedo/davFoundation/dav-js > gulp jest

[21:27:09] Using gulpfile ~/davFoundation/dav-js/gulpfile.js [21:27:09] Starting 'jest'... PASS src/drone-charging/NeedParams.test.ts NeedParams class serialize method ✓ should return serialized NeedParams object with the current values (8ms) deserialize method ✓ should return a NeedParams instance (1ms) ✓ should return deserialize NeedParams instance with the current parameters (1ms)

DAVFoundation / dav-js