TravisCI: try using --insecure option to hg
TravisCI: try using --insecure option to hg

to allow mercurial to access the Eigen repo.

MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3