package(harp): update harp version to fix async errors

Author: naomiblack

package.json

@@ -44,7 +44,7 @@
     "gulp-task-listing": "^1.0.1",
     "gulp-util": "^3.0.6",
     "gulp-watch": "^4.3.4",
-    "harp": "^0.20.1",
+    "harp": "^0.20.3",
     "html2jade": "^0.8.4",
     "indent-string": "^2.1.0",
     "jasmine-core": "^2.3.4",