Add has to the language chains.
This is to address the awkward phrasing that arises from chaining assertions off of properties.
.that.has.members([1, 2, 3])
Add `has` to language chains
Coverage remained the same when pulling 4ea26a7 on duncanbeevers:add_has into 564af34 on chaijs:master.
Fine by me. @logicalparadox ?