* spec/bundler/spec_helper.rb: there are no reason to refuse ':' and '-' in the
path of spec files. especially, ':' is always contained on Windows.
* spec/bundler/spec/helper.rb: open3.rb is also supported on Windows.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60610 b2dd03c8-39d4-4d8f-98ff-823fe69b080e