Use dist:trusty Switch to clang 5.0 and 4.0 is removed from apt repo.
Use dist:trusty
Switch to clang 5.0 and 4.0 is removed from apt repo.

google/libprotobuf-mutator,google/libprotobuf-mutator,vitalybuka/libprotobuf-mutator,vitalybuka/libprotobuf-mutator