add back compat code that will be removed next api breaking release.

Author: ctalkington

lib/archiver.js

@@ -38,6 +38,12 @@ archiver.registerFormat = function(format, module) {
   }
 
   formats[format] = module;
+
+  // backwards compat - to be removed in 0.14
+  var compatName = 'create' + format.charAt(0).toUpperCase() + format.slice(1);
+  archiver[compatName] = function(options) {
+    return archiver.create(format, options);
+  };
 };
 
 archiver.registerFormat('zip', require('./plugins/zip'));