Reduce jobs run on Travis
Reduce jobs run on Travis

Skip building and testing restic with Go 1.3, 1.4 and 1.6 on osx.

kurin/restic,byo/restic,middelink/restic,jayme-github/restic,kurin/restic,arithmetric/restic,middelink/restic,restic/restic,ckemper67/restic,ar-jan/restic,byo/restic,restic/restic,ar-jan/restic,fawick/restic,jayme-github/restic,stuertz/restic,mappu/restic,bchapuis/restic,fawick/restic,stuertz/restic