GSoC 2021: Unit Tests for AtlasMaker Server and its utility functions added.

[adityaofficial10]

What has been added?

• Unit tests for Atlasmaker-mri file have been added.
• Unit tests for Atlasmaker utility functions have been added.
• Some dependencies like sinon have been added for testing purposes.

What will be the effect? This will bring up the coverage by a considerable amount and launch us on our goal of atleast 60% coverage at the end of this program. Master Branch:

This Branch:

Also, I have merged the tests for some utility functions with the MRI module tests. So they would be there in the next week's PR. @katjaq @r03ert0 Kindly have a look..

[katjaq]

That looks great! Thank you for your work! Will go and merge! :) :rocket: