Update to 0.48

Upstream changes:
0.48      2016-12-07 01:15:14Z
        - reverted is_Foo and to_Foo refactoring [from 0.47] for now, so they
          can be reworked

0.47      2016-12-07 00:40:34Z
        - allow type libraries built with MooseX::Types::Combine to be
          combined with MooseX::Types::Combine. (GH #1, Mark Fowler).
        - made the exported is_Foo and to_Foo subs much faster, especially for
          type constraints which can be inlined [reverted in 0.48]

(wen)