Travis: Fix warnings in build config validation
Travis: Fix warnings in build config validation

It said:

Build config validation
root: deprecated key sudo (The key `sudo` has no effect anymore.)
root: missing os, using the default linux
root: key matrix is an alias for jobs, using jobs

boldtrn/graphhopper,graphhopper/graphhopper,graphhopper/graphhopper,boldtrn/graphhopper,boldtrn/graphhopper,boldtrn/graphhopper,graphhopper/graphhopper,graphhopper/graphhopper