Add META6.json

Add META6.json to the project. Dependencies should be caught by:

cat `find ./www ./lib -name '*raku*' -print` | egrep -i '^use\s+' | egrep -v 'Pheix'

Add test install to ci.bash:

zef install .

Perform test installation and further testings at http://rakudist.raku.org/