A bit of refactoring for apply_ck
First changes to travis for building with CUDA
Attempting to install CUDA
First attempt to build with CUDA on travis
Disabled unnecessary builds on travis
Second attempt with CUDA on travis
Third attempt with CUDA on travis
4th attempt with CUDA on travis
5th attempt with CUDA on travis
Remove the now-unused DYND_PP_OUTER preprocessor metaprogram
Remove the unused DYND_PP_JOIN_OUTER preprocessor metaprogram

The OUTER algorithms were much larger than the others in gen.hpp,
we have replaced their usage with C++11 variadic templates. By
removing them, the preprocessor has a bit less text to process.
Disabled testing with CUDA on travis
Attempting to build CUDA tests, but not run them
Merge pull request #174 from mwiebe/pp_simplify

Remove the OUTER preprocessor macro metaprograms
Merge pull request #173 from izaid/apply

CUDA on Travis CI