* Adding testing-library dependencies, and bumping frontend-build to be compatible with them.
* Adding a function to initialize the redux store
We need to use it in a few places. Seems worth not-repeating, since they can easily get out of sync. In general, tests should only test the parts of the store they care about, as well.
* Adding function to initialize a mock application.
Ultimately I’d like to move this to frontend-platform as an alternative to ‘initialize’ for tests. ‘initialize’ is an async function which complicates matters.
* Using more explicit assertions for courseware reducer fields.
This removes the need for the snapshot file, and ensures our test is more resilient to unrelated changes in the store.
Also added a few more stages of assertions to some of the tests, showing that they have the right values over time.
* Adding a helper to build a simple course blocks response.
We can use this in the courseware data tests, and shortly in the tests for CoursewareContainer.
* Modifying sequenceMetadata factory to allow multiple units.
This will help us test sequence navigation’s behavior more fully by having multiple units in a sequence.
* A little linting and cleanup.
* Adding first round of tests for CoursewareContainer.
Tests loading, sequence navigation/unit rendering, and ‘denied’ states.
Subsequent tests will add tests for handlers.
