Fixed tests by turning off agent subsystems in IOSwitchboard tests.
Fixed tests by turning off agent subsystems in IOSwitchboard tests.

This fixes the changes introduced in
354bca1311c5b3b98a2a50689f0fba6a033e743d to enable building on OS X.

Review: https://reviews.apache.org/r/54702/

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