OnlineLinearMachine::get_w(): Copy weight before passing them to SGVector to prevent double-free on destruction.
Merge pull request #1196 from tklein23/double_free_hotfix

Fixed double-free when using "SGVector<float32_t> OnlineLinearMachine::get_w()"
Fix json version on travis
Travis: fix cwd before building
refactor likelihood models
Merge pull request #1200 from votjakovr/feature/gp_refactoring

refactor likelihood models
change default value of the derivative wrt hypers
Merge pull request #1201 from votjakovr/feature/gp_refactoring

change default value of the derivative wrt hypers