use a fresh sandbox for each test

Switching from cabal-dev to cabal sandboxes was causing everything to be
installed to --global, which in turn caused packages to not be
reinstalled, which was causing incorrect ranges to be returned.

Clearing the sandbox on every test makes the compilation a lot longer :(
install QuickCheck

since I use Make instead of cabal to run my tests, I don't have a way
to specify that QuickCheck is required for testing. So I just install
it before running the tests.
expect a lower limit for containers

After all, the test programs don't use any function from containers, so
any version which still compiles should be fine. I don't know why
cabal-rangefinder was previously returning a different lower-bound.