Added persistent volume endpoint test without authentication.
Added persistent volume endpoint test without authentication.

Added persistent volume endpoint tests with HTTP authentication
disabled.

The persistent volume endpoint tests allow volume creation and
destruction when HTTP authentication is disabled; this patch introduces
a test for this scenario:
  `PersistentVolumeEndpointsTest.NoAuthentication`.

Review: https://reviews.apache.org/r/42362/

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