PIM-3070: Remove useless files
PIM-3070: Remove dir content and task option
PIM-3070: Remove import/export directories from requirements
PIM-3070: Clean directories
PIM-3070: Update CHANGELOG.md
PIM-3070: Update README.md
Merge pull request #1390 from akeneo/PIM-3070

PIM-3070: Remove content of file 'archive' and 'upload'