DNF plugin: Update for Python 3.6
DNF plugin: Update for Python 3.6

irushchyshyn/portingdb,irushchyshyn/portingdb,ari3s/portingdb,fedora-python/portingdb,ari3s/portingdb,fedora-python/portingdb,ari3s/portingdb,irushchyshyn/portingdb,fedora-python/portingdb,ari3s/portingdb,irushchyshyn/portingdb