Cover Akeneo TableAttributeBundle with tests

[flagbird]

Currently there are still tests missing for this bundle for the PHP and Javascript part.

• Check if the code is testable and create tests
• Look into the need of integration tests with Akeneo, so there can be checks for BC
• Make tests run with all supported Akeneo versions
  • For easier implementation always test with the latest patch version. This can be improved later

[amansilla]

Maybe it will be a better idea to create separate issues for every bullet otherwise this issue will be the never ending story. Or is this here everything related to EndToEnd tests?

[flagbird]

#18 is already handling those, because the migration (and future migrations) benefits from tests.

[amansilla]

Great, so that means this can be closed once #18 is merged.

[amansilla]

I'll close this issue since #18 which includes tests got merged.