replace long rollup cli with rollup.config.js

package.json

@@ -3,14 +3,14 @@
   "version": "5.6.0",
   "description": "Utility functions and common patterns for MobX",
   "main": "mobx-utils.umd.js",
-  "module": "lib/mobx-utils.js",
+  "module": "mobx-utils.module.js",
   "jsnext:main": "mobx-utils.module.js",
   "react-native": "mobx-utils.module.js",
   "typings": "lib/mobx-utils.d.ts",
   "sideEffects": false,
   "scripts": {
     "prettier": "prettier --write \"**/*.js\" \"**/*.jsx\" \"**/*.tsx\" \"**/*.ts\"",
-    "build": "tsc -p src && rollup lib/mobx-utils.js -e mobx -g mobx:mobx -o mobx-utils.umd.js -f umd --name mobxUtils && rollup lib/mobx-utils.js -e mobx -o mobx-utils.module.js -f es",
+    "build": "tsc -p src && rollup -c",
     "watch": "jest --watch",
     "test": "jest",
     "prepublishOnly": "npm run build && npm run build-docs",

rollup.config.js

@@ -0,0 +1,24 @@
+export default {
+    input: "lib/mobx-utils.js",
+    output: [
+        {
+            format: "umd",
+            file: "mobx-utils.umd.js",
+            name: "mobxUtils",
+            globals: {
+                mobx: "mobx",
+            },
+        },
+        {
+            format: "es",
+            file: "mobx-utils.module.js",
+        },
+    ],
+    external: ["mobx"],
+    onwarn: function (warning, warn) {
+        // https://github.com/rollup/rollup/wiki/Troubleshooting#this-is-undefined
+        if ("THIS_IS_UNDEFINED" === warning.code) return
+
+        warn(warning)
+    },
+}