router/hipache: starting to implement router that uses hipache

This router just push routes to redis. This is where configuration for
hipache live :)
travis: add redis
router/hipache: unexport router type
router/hipache: improve error handling
router/hipache: add RemoveRoute implementation
router: also return error on Addr
provision/lxc: fix Router.Addr calls
router/hipache: implement Addr method

Now it's complete. Let's register it :-)
router/hipache: rename the router type

The old name would conflict with the router package.
hipache/router: register the router for use in other packages
router/hipache: add documentation
route/testing: validate routes presence in Addr