query: unit test for hy_query_filter_provides().
query: unit test for hy_query_filter_provides().

it has not been used much and concerns it doesn't work emerged.

edynox/libdnf,rpm-software-management/libhif,rpm-software-management/libdnf,rpm-software-management/libhif,edynox/libdnf,Conan-Kudo/libhif,rpm-software-management/libhif,rpm-software-management/libdnf,cgwalters/libhif,Conan-Kudo/libhif,cgwalters/libhif,rpm-software-management/libdnf,rpm-software-management/libdnf,Conan-Kudo/libhif,rpm-software-management/libhif,edynox/libdnf,Conan-Kudo/libhif,hughsie/libhif,hughsie/libhif,hughsie/libhif,cgwalters/libhif,cgwalters/libhif,edynox/libdnf,hughsie/libhif