Add directory or bundle loading support

[egeloen]

Hey!

Currently, this extension only allows to load file by file and don't provide a way to load a directory or a bundle. It would not be a problem if I don't rely on a data loader but I do and so, I can't really rely on this extension.

Then, this PR tries to add support for a directory or a bundle without breaking the BC. For bundle, I don't pass an env otherwise I would need to break the BC.

You can load a directory or a bundle with for example:

Given the following fixtures are loaded:
    | @AcmeDemoBundle    |
    | /path/to/directory |

What do you think?

[theofidry]

I'm not so found of the if/elseif/else, it makes it hard to read IMO:

if (0 === strpos($fixturesFile, '/') && is_dir($fixturesFile)) {
    $fixtureDirectories[] = $fixturesFile;
    unset($fixturesFiles[$key]);

    continue;
}

if (0 === strpos($fixturesFile, '@') && false === strpos($fixturesFile, '.')) {
    $fixtureBundles[] = $this->kernel->getBundle(substr($fixturesFile, 1));
    unset($fixturesFiles[$key]);

    continue;
}

$fixturesFiles[$key] = sprintf('%s/%s', $this->basePath, $fixturesFile);

[egeloen]

We can't put condition in a single if and we still need to nest the if in order to not break the logic. If a fixtures file starts with a / or an @ and is not a directory then, we must not use the base path. Anyway, I have split it in order to not rely on if/elseif/else :)

[egeloen]

All comments have been applied!

[theofidry]

Great, thanks very much for the work @egeloen :)