Update dependency test-framework-smallcheck

[bitemyapp]

http://hackage.haskell.org/package/test-framework-smallcheck is old & abandoned.

The hackage page recommends http://hackage.haskell.org/package/tasty-smallcheck --- looks like that won't go anywhere for awhile :)

[hvr]

Well, you can't simply swap out test-framework-smallcheck with tasty-smallcheck, you'll have to replace the complete test framework....

Ironically, currently test-framework has a better compatibility range regarding GHC versions than tasty does (test-framework supports GHC 7.0/7.2, as well as GHC 8.0, which tasty doesn't...)

[clinty]

Switching everything from test-framework to tasty is not particularly complicated.