Update dependency vuepress to v1.3.0

Author: renovate-bot

package.json

@@ -4,6 +4,6 @@
     "docs:build": "vuepress build docs"
   },
   "devDependencies": {
-    "vuepress": "1.2.0"
+    "vuepress": "1.3.0"
   }
 }