Add https://github.com/darrenf/p6-test-declare (#396)

`Test::Declare` is a rudimentary way to express test scenarios in a fairly declarative sense. Assuming I understand the word 'declarative' properly.

Author: darrenf

META.list

@@ -878,3 +878,4 @@ https://raw.githubusercontent.com/mryan/perl6-Slang-AltTernary/master/META6.json
 https://raw.githubusercontent.com/zoffixznet/perl6-Games-TauStation-DateTime/master/META6.json
 https://raw.githubusercontent.com/FCO/JSON-Stream/master/META6.json
 https://raw.githubusercontent.com/ohmycloud/fanfou-p6/master/META6.json
+https://raw.githubusercontent.com/darrenf/p6-test-declare/master/META6.json