use Type::Tiny for type checking?

[nics]

http://blogs.perl.org/users/toby_inkster/2014/08/typetiny-1000000-released.html

no new dependencies since it's now used by Moo

[nics]

informative blog post here: http://blogs.perl.org/users/toby_inkster/2017/05/typetiny-12-coming-soon.html