test: implemented new integrative expirement tests

[lbarbMITRE]

Closes #310

[jkglasbrenner]

In preparation for review, I merged #324 into dev, squashed this branch's commits, and rebased it on dev.

[jkglasbrenner]

Looks good to me. I did some minor cleanup by running black over test_experiment.py and doing some minor editing of the docstrings. The editing was mostly structural, I wanted the scenarios to be formatted as block literals. In restructured text, that can be done by ending a sentence with :: and indenting the next block of text, see below for an example.

def test_register_experiment(client: FlaskClient, db: SQLAlchemy) -> None:
    """Tests that experiments can be registered following the scenario below::

        Scenario: Registering an Experiment
            Given I am an authorized user,
            I need to be able to submit a register request,
            in order to register an experiment.

    This test validates by following these actions:

    - A user registers two experiments, "mnist_name" and "mnist_id".
    - The user is able to retrieve information about each experiment using the
      experiment id or the unique experiment name.
    - In both cases, the returned information matches the information that was provided
      during registration.
    """