The old 6.4 url doesn't work anymore. Added -v version and -s disk size options
The script now figures out the name according the version. Cleanup script unregister and remove vm.
Merge pull request #2 from DemandCube/lih

Lih
fixing logical flow to create .box before deleting the vm files
Merge pull request #3 from lazaruslarue/fix_dynamic_vars

fixing logical flow to create .box before deleting the vm files
Merge https://github.com/DemandCube/vagrant-centos