Seed command will output the seeded classes.

Signed-off-by: Isern Palaus <ipalaus@ipalaus.com>
Merge pull request #2640 from ipalaus/feature/seeders-output

Add more informative output to the seed command
Fixed tests for DatabaseSeederTest.

Signed-off-by: Isern Palaus <ipalaus@ipalaus.com>
Merge pull request #2641 from ipalaus/feature/seeders-output-tests

Fixed tests for DatabaseSeederTest
Increase memory limit for framework tests.
Fix Str::contains(), startsWith() and endsWith() with empty needles.

The behavior in these cases has been unified:
- return false
- no longer produce warnings
Optimize Str::endsWith()
Docblock and code uniformization in Str class