added notice that a field must change
made comment adjustments for #289
Make resolveUri and resolvePath behavior consistent when there is no file
Don't try to generate the file's URL if there is no file in the VichFileType
Merge pull request #289 from Nemo64/patch-1

added notice that a field must change
Prepare 0.10.0 release
Add a few functional tests
Remove useless steps in the travis-ci configuration
Remove useless dependencies for functional tests
Fix test dependencies
Switch to PSR-4