Readme: invalid link (Salesforce::Vagrant)

[brayniac]

the Salesforce::Vagrant link in readme results in 404 http://github.com/forcedotcom/SalesforceVagrant

[chorankates]

I FOUND THE OLD REPOSITORY!

unfortunately when i wrote that line in documentation, i was really thinking of Perl::Koans, as that's what SFDC has let me open source. i never went through the process for Salesforce::Vagrant though, so it never actually made it outside of the company.

i'll update documentation. thanks for keeping me honest @brayniac