cosas v0.8.0

Cosas is a library for doing macros-free type-dependent generic programming in Scala:

1. Dependent functions which can be parametric and composed. All operations are implemented as dependent functions. They can wrap std FunctionXs.
2. KLists as heterogeneous lists with a bound on the their types, covariant on both element types and bound. They are now a basic building block of the library. Interoperable with std Lists. Support for basic dependently typed operations on them: foldLeft and foldRight, map, etc. Common functions on KLists implemented in terms of these combinators.
3. Types include now product and function types. Records are wrappers over product types with no duplicate elements. Denotations are covariant on the value. Removed subset types.
4. code reorg there are now separate packages instead of objects
5. test coverage is almost 100% now. Set up codacy and scoverage.
6. drop Scala 2.10 due to the amazing amount of workarounds needed, and 2.12 being already in milestone stage.
7. drop shapeless dependency cosas is now dependency-free.