removed default param, unsupported in Node 4.5 LTS

Author: samthor

lib/gulp.js

@@ -113,7 +113,7 @@ module.exports = function() {
     }
   };
 
-  return function(compilationOptions={}, pluginOptions={}) {
-    return new CompilationStream(compilationOptions, pluginOptions);
+  return function(compilationOptions, pluginOptions) {
+    return new CompilationStream(compilationOptions || {}, pluginOptions || {});
   };
 };