Display coverage results by Git commit / id

[ORESoftware]

One big enhancement to this project, would be to allow to HTTP POST coverage objects to the server by ID. The most common ID I think to use would be a Git commit ID.

So the results could be retrieved via:

GET /coverage/<id>

This would allow developers to have a running server that was solely responsible for displaying test coverage results, and we could see the coverage results for each different commit.

Otherwise..we might have to spin up a new server for each commit, and that's just not very seamless.

AFAICT this would be a huge win for this project.

So when POSTing results, it would be something like:

    let obj = await driver.executeScript('return window.__coverage__;');
    let str = JSON.stringify(obj);

    let options = {
      port: port,
      host: host,
      path: `/coverage/client?id=${id}`,
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
      }
    };

    let req = http.request(options, cb);

To make minimal changes to code base, we could pass the id as a query string parameter.