add TAP::Harness6 leont++

Author: FROGGS

META.list

@@ -243,3 +243,4 @@ https://raw2.github.com/hoelzro/p6-io-string/master/META.info
 https://raw2.github.com/hoelzro/p6-algorithm-lcs/master/META.info
 https://raw2.github.com/Nami-Doc/Sprockets.pl/master/META.info
 https://raw2.github.com/grondilu/clifford/master/META.info
+https://raw2.github.com/Leont/tap-harness6/master/META.info