Remove quota-class-* commands from v3 shell

Commit 1b15b23b0a629e00913a40c5def42e5ca887071c removed the
os-quota-class-sets v3 API from Nova in Icehouse.  This change removes
the corresponding client code.

Closes-Bug: #1331095

Change-Id: Iaa2f4063e0f671da5a54ff89d0f1c1780a2687c4
Merge "Remove quota-class-* commands from v3 shell"