fix import statements for nodejs 12.x.x ES module specifier resolution

exclude unnecessary files from tarball

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "node-fetch-cookies",
-  "version": "1.2.2",
+  "version": "1.2.3",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {

package.json

@@ -1,11 +1,14 @@
 {
   "name": "node-fetch-cookies",
-  "version": "1.2.2",
+  "version": "1.2.3",
   "description": "node-fetch wrapper that adds support for cookie-jars",
   "main": "src/index.mjs",
   "engines": {
     "node": ">=10.0.0"
   },
+  "files": [
+    "src/"
+  ],
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
   },

src/cookie-jar.mjs

@@ -1,6 +1,6 @@
 import fs from "fs";
 import url from "url";
-import Cookie from "./cookie";
+import Cookie from "./cookie.mjs";
 
 export default class CookieJar {
     constructor(flags, file, cookies) {

src/index.mjs

@@ -1,6 +1,6 @@
 import fetch from "node-fetch";
-import CookieJar from "./cookie-jar";
+import CookieJar from "./cookie-jar.mjs";
-import Cookie from "./cookie";
+import Cookie from "./cookie.mjs";
 
 async function cookieFetch(cookieJars, url, options) {
     let cookies = "";