Added Waffle.io badge.
Added HList.collect(Poly) & Tuple.collect(Poly)
Merge pull request #146 from stacycurl/collect

Added HList.collect(Poly) & Tuple.collect(Poly) (#130)
Tests for the length method of HLists
Fix in Length implicits

- Makes HNil.length compiles
- Adds HNil.length to the tests
Added method .toHList to Sized
Added method .toSized[M] to HList and tuples