Tutorial is not working

[gaurav-dalvi]

Error

vagrant up
Ignoring nokogiri-1.6.3.1 because its extensions are not built.  Try: gem pristine nokogiri --version 1.6.3.1
Ignoring unf_ext-0.0.7.1 because its extensions are not built.  Try: gem pristine unf_ext --version 0.0.7.1
Bringing machine 'netplugin-node1' up with 'virtualbox' provider...
Bringing machine 'netplugin-node2' up with 'virtualbox' provider...
Bringing machine 'netplugin-node3' up with 'virtualbox' provider...
There are errors in the configuration of this machine. Please fix
the following errors and try again:

vm:
* The host path of the shared folder is missing: bin

http://contiv.github.io/documents/tutorials/container-101.html