Added QoS module loader to ::create() factory.
Added QoS module loader to ::create() factory.

Review: https://reviews.apache.org/r/35281

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