Build and run the provided tests in %check. The locale needs to be
overriden to C.UTF-8 to make the Qt4 tests pass due to an issue with
Japanese character handling.
It is possible to disable the tests by building with `--without test`
(for example `fedpkg mockbuild --without test`).
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>