PIM-2905 Removed mimetype validation

MimeType guessing is unreliable
Allow to count options in behat
PIM-2754 : fix cs
Merge pull request #1256 from akeneo/behat_fix

Allow to count options in behat
Merge pull request #1255 from akeneo/PIM-2905

PIM-2905 Removed mimetype validation
PIM-2754 : fix PMD
Merge branch 'master' of github.com:akeneo/pim-community-dev
Fix PMD
Merge branch 'master' of github.com:akeneo/pim-community-dev
Fix PHPCS
PIM-2869 : use a platform mirror tag to avoid issue with deps
PIM-2754: Introduction of the datagrid support resolver