Add travis config file for travis-ci.org.
Add travis config file for travis-ci.org.

define a travis config file to build debug and release configs on clang
and gcc for linux and osx.

Review: https://reviews.apache.org/r/28683

craimbert/mesos,Gilbert88/mesos,yuquanshan/customizedMesos,reneploetz/mesos,abudnik/mesos,jpeach/mesos,dforsyth/mesos,neilconway/mesos,abudnik/mesos,Aman-Jain-14/customizedMesos,Aman-Jain-14/customizedMesos,reneploetz/mesos,andschwa/mesos,zmalik/mesos,zmalik/mesos,andschwa/mesos,zmalik/mesos,craimbert/mesos,gsantovena/mesos,Aman-Jain-14/customizedMesos,zmalik/mesos,jpeach/mesos,chhsia0/mesos,abudnik/mesos,neilconway/mesos,yuquanshan/customizedMesos,jpeach/mesos,dforsyth/mesos,abudnik/mesos,asamerh4/mesos,jpeach/mesos,verizonlabs/mesos,chhsia0/mesos,Gilbert88/mesos,gsantovena/mesos,zmalik/mesos,gsantovena/mesos,yuquanshan/customizedMesos,chhsia0/mesos,jpeach/mesos,neilconway/mesos,andschwa/mesos,asamerh4/mesos,verizonlabs/mesos,Gilbert88/mesos,abudnik/mesos,jpeach/mesos,craimbert/mesos,verizonlabs/mesos,dforsyth/mesos,craimbert/mesos,asamerh4/mesos,reneploetz/mesos,neilconway/mesos,Gilbert88/mesos,verizonlabs/mesos,reneploetz/mesos,reneploetz/mesos,dforsyth/mesos,Aman-Jain-14/customizedMesos,kaysoky/mesos,craimbert/mesos,kaysoky/mesos,reneploetz/mesos,craimbert/mesos,zmalik/mesos,asamerh4/mesos,verizonlabs/mesos,andschwa/mesos,yuquanshan/customizedMesos,verizonlabs/mesos,jpeach/mesos,kaysoky/mesos,Gilbert88/mesos,chhsia0/mesos,yuquanshan/customizedMesos,andschwa/mesos,kaysoky/mesos,abudnik/mesos,Aman-Jain-14/customizedMesos,gsantovena/mesos,dforsyth/mesos,kaysoky/mesos,abudnik/mesos,kaysoky/mesos,dforsyth/mesos,Gilbert88/mesos,Gilbert88/mesos,Aman-Jain-14/customizedMesos,verizonlabs/mesos,chhsia0/mesos,neilconway/mesos,Aman-Jain-14/customizedMesos,asamerh4/mesos,zmalik/mesos,kaysoky/mesos,asamerh4/mesos,chhsia0/mesos,asamerh4/mesos,gsantovena/mesos,reneploetz/mesos,gsantovena/mesos,dforsyth/mesos,neilconway/mesos,andschwa/mesos,gsantovena/mesos,yuquanshan/customizedMesos,yuquanshan/customizedMesos,neilconway/mesos,craimbert/mesos,chhsia0/mesos,andschwa/mesos