improved stream mocks for older versions and increased compatabity from 0.8 up

grunt/config/prompt.js

@@ -0,0 +1,12 @@
+module.exports = {
+  confirm_release: {
+    options: {
+      questions: [{
+        config: 'confirm.release',
+        type: 'confirm',
+        message: 'Are you sure you want to overwrite/release version <%= package.version %> of elasticsearch-js',
+        default: false
+      }]
+    }
+  }
+};