Assert slave not master.
Assert slave not master.

Test asserting on master that has to be slave.

Review: https://reviews.apache.org/r/22779

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