CreateCacheCommand waiting for a number of members should be optional

CLI allows the user to create a cache on all the nodes with create <newCache> like <existingCache>;.

It doesn't specify an expected number of members, so CreateCacheCommand shouldn't block. However, after of the ISPN-5534 fix, the CreateCacheCommand invocation would always time out waiting for 0 members. This causes ClusteredCLITest.testCreateCluster() to always fail.