update package deps, remove extra dev options

package.json

@@ -7,7 +7,6 @@
   "main": "dist/vue-select.js",
   "license": "MIT",
   "scripts": {
-    "start": "npm run dev",
     "serve": "webpack-dev-server --config build/webpack.dev.conf.js --hot --progress -d",
     "serve:docs": "vuepress dev docs",
     "build": "cross-env NODE_ENV=production webpack --config build/webpack.prod.conf.js --progress",
@@ -26,15 +25,15 @@
     "ajv": "6.8.1"
   },
   "devDependencies": {
-    "@babel/core": "^7.2.2",
-    "@babel/plugin-transform-runtime": "^7.2.0",
-    "@babel/preset-env": "^7.3.1",
-    "@babel/runtime": "^7.3.1",
+    "@babel/core": "^7.4.0",
+    "@babel/plugin-transform-runtime": "^7.4.0",
+    "@babel/preset-env": "^7.4.2",
+    "@babel/runtime": "^7.4.2",
     "@vue/test-utils": "^1.0.0-beta.29",
     "autoprefixer": "^9.4.7",
     "babel-core": "^7.0.0-bridge.0",
-    "babel-loader": "^8.0.0",
-    "chokidar": "^2.0.4",
+    "babel-loader": "^8.0.5",
+    "chokidar": "^2.1.5",
     "coveralls": "^3.0.2",
     "cross-env": "^5.2.0",
     "css-loader": "^2.1.0",
@@ -53,18 +52,18 @@
     "sass-loader": "^7.1.0",
     "terser-webpack-plugin": "^1.2.3",
     "url-loader": "^1.1.2",
-    "vue": "^2.6.4",
+    "vue": "^2.6.10",
     "vue-html-loader": "^1.2.4",
-    "vue-jest": "^3.0.3",
-    "vue-loader": "^15.6.2",
+    "vue-jest": "^3.0.4",
+    "vue-loader": "^15.7.0",
     "vue-style-loader": "^4.1.2",
-    "vue-template-compiler": "^2.6.4",
+    "vue-template-compiler": "^2.6.10",
     "vuepress": "^0.14.8",
     "vuex": "^3.1.0",
-    "webpack": "^4.28.0",
-    "webpack-cli": "^3.2.1",
-    "webpack-dev-server": "^3.1.10",
-    "webpack-merge": "^0.13.0"
+    "webpack": "^4.29.6",
+    "webpack-cli": "^3.3.0",
+    "webpack-dev-server": "^3.2.1",
+    "webpack-merge": "^4.2.1"
   },
   "jest": {
     "moduleFileExtensions": [