Remove hard dependencies to work with Vagrant 1.7.4, 1.8.7, 1.9.1
Remove hard dependencies to work with Vagrant 1.7.4, 1.8.7, 1.9.1

Signed-off-by: Stefan Scherer <2fe843265e65a9540d5df64f4bed2ee6b7ca283e@icloud.com>

plossys/vagrant-vcloud,frapposelli/vagrant-vcloud,frapposelli/vagrant-vcloud,plossys/vagrant-vcloud