Fix symlink support

lib/rel_symlink.js

@@ -8,9 +8,8 @@ var relative = require('path').relative
 
 module.exports = function relSymlink (src, dest) {
   // Turn it into a relative path when not in win32.
-  var rel = process.platform === 'win32'
-    ? relative(dirname(dest), src)
-    : src
+  var isWindows = process.platform === 'win32'
+  var rel = isWindows ? src : relative(dirname(dest), src)
 
   return symlink(rel, dest, 'junction')
 }