Update pool command syntax.
Update pool command syntax.

Former-commit-id: df68fd28a5cc368714eedccc271cc6cd95dd3b47
alexhersh/libcalico,insequent/libcalico,TrimBiggs/libnetwork-plugin,caseydavenport/libcalico,tomdee/libcalico,TrimBiggs/libcalico,plwhite/libcalico,djosborne/libcalico,tomdee/libnetwork-plugin,projectcalico/libcalico,robbrockbank/libcalico,L-MA/libcalico,projectcalico/libnetwork-plugin,TrimBiggs/libnetwork-plugin,Symmetric/libcalico