[Feature] Auto-generated functional tests for List, New, Edit, Show builders

[ioleo]

This is not a priority, but would be a great feature, so once I have some time I'll do it.

There are some points to discuss here though. In my projects I use doctrine/doctrine-fixtures-bundle and liip/functional-test-bundle. I don't know the equivalents for Propel, I don't know if doctrine-fixtures-bundle works for Doctrine ODM.

@eymengunay I've seen your cost PRs to do doctrine/mongodb-odm and fix our Doctrine ODM code, maybe you can answer my questions above?

@cedriclombardot @CayetanoSoriano @sescandell I'd introduce a hard dependency to liip/functional-test-bundle. What do you think? Maybe there is some better way to test I'm not aware of?

[ioleo]

@sescandell I think this issue has to wait after #515, so we will generate tests only for partial views. If list by default consists of a table, scopes and filters, then if all tests are green for each partial view, we can assume that list view shows correctly.

We can benefit from that approach when we create a custom page where on the left we have a nested tree (folders), and on the right list table (files inside selected folder), then we don't have to create custom tests.

If partial test for nested tree is green and partial test for list is green, then we can assume our custom view also renders correctly.