Added more tests
Fixed url of the Travis badge

[ci skip]
Moved the license to the top of the files
Prefer exact matches in the named selector

This uses the approach implemented by @bevanr in #386 but rebuilds it on
top of the latest Mink where the NamedSelector was changed a lot.
It also supports using the 'named' selector for findAll call, which was
not the case in the original implementation.