PSR-7 Uploaded File compatibility

[alextech]

This patch provides changes to both the File\Upload and File\UploadFile validators to provide support for validating PSR-7 UploadedFileInterface instances.

[samsonasik]

@alextech please rebase against develop branch to only show your commit:

git checkout develop
git pull https://github.com/zendframework/zend-validator.git develop
git checkout feature/psr-uploadfile
git rebase develop

If you found conflict, you can fix it in the file conflicted, and run:

git add . && git rebase --continue

Lastly, force push:

git push --force origin feature/psr-uploadfile

[alextech]

@samsonasik Thank you for instructions! I saved them to my notes.

[weierophinney]

Thanks, @alextech!