Few bugs in vnffgd code

[bharaththiruveedula]

There are few things I found while deploying VNFFG. For example
1)the argument we passed is vim_auth in https://github.com/openstack/tacker/blob/master/tacker/nfvo/nfvo_plugin.py#L374 but abstract driver has "vim_obj" https://github.com/openstack/tacker/blob/master/tacker/nfvo/drivers/vim/abstract_vim_driver.py#L95

2)Here https://github.com/openstack/tacker/blob/master/tacker/nfvo/drivers/vim/openstack_driver.py#L253 it must be resource_type otherwise it will call "list_tenant_net", the expected call must be "list_networks"

3)while getting the neutron client, I think we have decode the password using fernet keys, as neutron call to list_network throws unauthorized error.