There is a problem due to hardcoded checks for version 1.9 of ruby on the code.
.../lib/ruby/gems/2.0.0/gems/net-ssh-2.6.2/lib/net/ssh/authentication/pageant.rb:45:in `<module:Win>': undefined method `typealias' for Net::SSH::Authentication::Pageant::Win:Module (NoMethodError)
I suppose the best approach is to assume the api will not change upwards, when it does it should be fixed. Instead of supporting only a few specific versions and having to fix everytime a new version is released.
I fixed locally and it seems fine, though I haven't run any tests.
I'll fork and apply my fix, if tests are ok I'll make a pull request.
I made a pull request (#86), though it hasn't got referenced here...
This should fix #85.
It's prefered to fallback to the newer api instead of checking for
versions before 1.9 and 1.9 and leaving others open to breakage.