Refactored resources validations into separate validators.
Refactored resources validations into separate validators.

Review: https://reviews.apache.org/r/30298

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