ESX 6 free license + flocker + vsphere-flocker-driver

[Kridev]

Using ESX 6 free license datacenter + flocker + vsphere flocker driver I get:

flocker-dataset-agent[33056]: {"exception": "twisted.internet.defer.FirstError", "reason": "FirstError[#7, [Failure instance: Traceback: <class 'vsphere_flocker_plugin.vsphere_blockdevice.VolumeCreationFailure'>:
(vim.fault.RestrictedVersion) {\n dynamicType = ,\n dynamicProperty = (vmodl.DynamicProperty) [],\n msg = 'Current license or ESXi version prohibits execution of the requested operation.',\n faultCause = ,\n faultMessage = (vmodl.LocalizableMessage) []\n}

If it's not possible to use free version, can you please add this requirement to readme?