SUBMARINE-586. Add the get/delete api & tests.

[lowc1012]

What is this PR for?

User can get/delete notebook instances with REST API
GET request to the URI (/api/v1/notebook/{id}) could get detailed info about the notebook with the notebook ID.
DELETE request to the URI (/api/v1/notebook/{id}) could delete the notebook instance with the notebook ID

What type of PR is it?

[Feature]

Todos

• - Task

What is the Jira issue?

SUBMARINE-586

How should this be tested?

travis CI

Screenshots (if appropriate)

Questions:

• Does the licenses files need update? No
• Is there breaking changes for older versions? No
• Does this needs documentation? No

[jiwq]

+1 Thanks @lowc1012 for the contribution. Will commit if no more comments.

[pingsutw]

Thanks @lowc1012 for the contribution.
one question, why dockerImage, kernelSpec, image are null?

[lowc1012]

@jiwq Thank you for your review!
@pingsutw I updated the JSON response. Please review it again. Thanks a lot!

[pingsutw]

Thanks @lowc1012, The update looks good to me.