[CBR-502] Txp.CoreSpec: print Quickcheck failure counterexamples
[CBR-502] Txp.CoreSpec: print Quickcheck failure counterexamples

input-output-hk/pos-haskell-prototype,input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype,input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype,input-output-hk/cardano-sl,input-output-hk/cardano-sl