Fixed Gemspec - Syntax fixes - Added dependency on nokogiri 1.5.5 to avoid issue with rbvmomi 	(https://github.com/vmware/rbvmomi/issues/31)
Fixed Gemspec
- Syntax fixes
- Added dependency on nokogiri 1.5.5 to avoid issue with rbvmomi
	(https://github.com/vmware/rbvmomi/issues/31)

frapposelli/vagrant-vcenter,gosddc/vagrant-vcenter,mmarseglia/vagrant-vcenter