fix exports entry for CommonJS

Author: dutu

package.json

@@ -1,14 +1,14 @@
 {
   "name": "poloniex-api-node",
-  "version": "3.1.0",
+  "version": "3.1.1",
   "description": "Simple node.js wrapper for Poloniex REST and WebSocket API.",
   "type": "module",
   "main": "./dist/cjs/poloniex.cjs",
   "module": "./lib/poloniex.mjs",
   "exports": {
     ".": {
       "import": "./lib/poloniex.mjs",
-      "require": "./dist/cjs/poloniex.js"
+      "require": "./dist/cjs/poloniex.cjs"
     }
   },
   "engines": {