Get QuickCheck 2.7 compatibility
Get QuickCheck 2.7 compatibility

Replace deprecated `printTestCase` by its replacement `counterexample`.
Note that commit 077c415a added a CPP-guarded fallback for QuickCheck < 2.7.

Signed-off-by: Klaus Aehlig <4ce51de36d9068cd7db2eec1151e0f3f95419008@google.com>
Reviewed-by: Petr Pudlak <9d19625f8ee825a2c398462ed335cbcf98f79c32@google.com>

Cherry-picked-from: 693db8a9e7a3e3b855350b9f558251bce1718d07
Signed-off-by: Petr Pudlak <9d19625f8ee825a2c398462ed335cbcf98f79c32@google.com>
Reviewed-by: Klaus Aehlig <4ce51de36d9068cd7db2eec1151e0f3f95419008@google.com>

ganeti/ganeti,ganeti/ganeti,leshchevds/ganeti,mbakke/ganeti,yiannist/ganeti,leshchevds/ganeti,mbakke/ganeti,yiannist/ganeti,leshchevds/ganeti,bitemyapp/ganeti,andir/ganeti,ganeti/ganeti,bitemyapp/ganeti,andir/ganeti,grnet/snf-ganeti,mbakke/ganeti,yiannist/ganeti,onponomarev/ganeti,andir/ganeti,grnet/snf-ganeti,onponomarev/ganeti