Add cjs build

Author: zackify

.gitignore

@@ -1,2 +1,3 @@
 node_modules
-lib
+lib
+cjs

package-lock.json

@@ -1,11 +1,11 @@
 {
   "name": "react-use-upload",
-  "version": "0.5.0",
+  "version": "0.5.1",
   "description": "",
   "main": "lib/index.js",
   "scripts": {
     "test": "tsc",
-    "build": "npx babel src --out-dir lib --extensions \".ts,.tsx\" && npm run create-types",
+    "build": "npx babel src --out-dir lib --extensions \".ts,.tsx\" && npx babel --plugins @babel/plugin-transform-modules-commonjs src --out-dir cjs --extensions \".ts,.tsx\" && npm run create-types",
     "create-types": "tsc --emitDeclarationOnly",
     "watch": "npx babel --watch src --out-dir lib",
     "example-server": "node -r esm ./example/server.js"
@@ -15,6 +15,7 @@
   "devDependencies": {
     "@babel/cli": "^7.4.4",
     "@babel/core": "^7.4.5",
+    "@babel/plugin-transform-modules-commonjs": "^7.4.4",
     "@babel/preset-react": "^7.0.0",
     "@babel/preset-typescript": "^7.3.3",
     "@types/react": "^16.8.19",