Re-enable clang / os x in .travis
Re-enable clang / os x in .travis

Change-Id: I45f6326f1b7da2d83eeee72fe44fd9626a288b5b

evolutional/flatbuffers,pjulien/flatbuffers,alexames/flatbuffers,evolutional/flatbuffers,pjulien/flatbuffers,alexames/flatbuffers,alexames/flatbuffers,DavadDi/flatbuffers,stewartmiles/flatbuffers,hgl888/flatbuffers,royalharsh/flatbuffers,google/flatbuffers,pjulien/flatbuffers,stewartmiles/flatbuffers,google/flatbuffers,stewartmiles/flatbuffers,google/flatbuffers,pjulien/flatbuffers,stewartmiles/flatbuffers,rw/flatbuffers,stewartmiles/flatbuffers,google/flatbuffers,google/flatbuffers,rw/flatbuffers,stewartmiles/flatbuffers,alexames/flatbuffers,alexames/flatbuffers,royalharsh/flatbuffers,pjulien/flatbuffers,google/flatbuffers,evolutional/flatbuffers,pjulien/flatbuffers,stewartmiles/flatbuffers,google/flatbuffers,stewartmiles/flatbuffers,alexames/flatbuffers,evolutional/flatbuffers,royalharsh/flatbuffers,google/flatbuffers,evolutional/flatbuffers,DavadDi/flatbuffers,rw/flatbuffers,alexames/flatbuffers,pjulien/flatbuffers,rw/flatbuffers,royalharsh/flatbuffers,google/flatbuffers,pjulien/flatbuffers,alexames/flatbuffers,stewartmiles/flatbuffers,google/flatbuffers,alexames/flatbuffers,DavadDi/flatbuffers,hgl888/flatbuffers,rw/flatbuffers,hgl888/flatbuffers,rw/flatbuffers,DavadDi/flatbuffers,hgl888/flatbuffers,royalharsh/flatbuffers,evolutional/flatbuffers,stewartmiles/flatbuffers,rw/flatbuffers,royalharsh/flatbuffers,google/flatbuffers,google/flatbuffers,rw/flatbuffers,DavadDi/flatbuffers,royalharsh/flatbuffers,evolutional/flatbuffers,hgl888/flatbuffers,DavadDi/flatbuffers,evolutional/flatbuffers,google/flatbuffers,evolutional/flatbuffers,evolutional/flatbuffers,evolutional/flatbuffers,alexames/flatbuffers,alexames/flatbuffers,google/flatbuffers,pjulien/flatbuffers,stewartmiles/flatbuffers,evolutional/flatbuffers,evolutional/flatbuffers,pjulien/flatbuffers,hgl888/flatbuffers,alexames/flatbuffers,alexames/flatbuffers,rw/flatbuffers,royalharsh/flatbuffers,stewartmiles/flatbuffers,rw/flatbuffers,royalharsh/flatbuffers,google/flatbuffers,stewartmiles/flatbuffers,pjulien/flatbuffers,royalharsh/flatbuffers,alexames/flatbuffers,pjulien/flatbuffers,alexames/flatbuffers,rw/flatbuffers,rw/flatbuffers