Fixed invalid JSON in scheduler HTTP API examples.
Fixed invalid JSON in scheduler HTTP API examples.

Review: https://reviews.apache.org/r/46781/

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