upgrade deps

Author: kazupon

package.json

@@ -34,7 +34,7 @@
     "vue-eslint-parser": "^7.0.0"
   },
   "devDependencies": {
-    "eslint": "^5.15.0 || ^6.0.0",
+    "eslint": "^5.15.0 || ^6.0.0 || ^7.0.0",
     "eslint-plugin-markdown": "^1.0.0",
     "eslint-plugin-vue-libs": "^3.0.0 || ^4.0.0",
     "lerna-changelog": "^1.0.0",
@@ -43,10 +43,10 @@
     "opener": "^1.5.1",
     "rimraf": "^3.0.0",
     "shipjs": "^0.20.0",
-    "vuepress": "^1.0.0-alpha.39"
+    "vuepress": "^1.5.2"
   },
   "engines": {
-    "node": ">=10.13.0 || >=11.10.1"
+    "node": ">=10.13.0 || >=12.0.0 || >= 14.0.0"
   },
   "files": [
     "lib"