Inconsistency between UI and backing data in Reports page

**TL;DR:**
- Display logic for `Approve` button seems to be inconsistent with the backing data for the UI.
- Filtering is not working unless page is refreshed.

After backstop tests are run, and backstop report page is opened (by running `ember backstop-report`), the `Approve` button, if present, comes back after switching between the `passed` and `failed` tabs.

Just to be clear, here is what I am referring to as the `passed` and `failed` tabs:

*Expectation:*
- The `Approve` button should not be present for tests that have already been approved.
- The test that was approved (by clicking on `Approve` button) should be filtered as passed.

*What actually happens:*
- The `Approve` button is present for tests that have already been approved.
- Filtering tests bases on passed/failed seems to be _not_ working. Tests that have been approved are still displayed in the failed category.

If the backstop report page is refreshed, then all the UI state seems to be updated/rendered correctly as per the backing data.

Here is a screen capture to illustrate the problem:
[Approve-button-bug.mov.zip](https://github.com/garris/BackstopJS/files/4366817/Approve-button-bug.mov.zip)