fix: use http module instead of fetch (#17)

allows usage of RCZ with NodeJS v14 and v16

src/index.ts

@@ -37,6 +37,7 @@ import { Command } from "commander";
 import semver from "semver";
 import { execSync } from "child_process";
 import { tmpdir } from "os";
+import { request } from "http";
 
 const GetConfig = async () => {
   if (fs.existsSync(path.join(process.cwd(), ".rczrc"))) {
@@ -105,6 +106,21 @@ const GetPostReleaseScript = async () => {
     return null;
   }
 };
+const isOnline = () => {
+  return new Promise<boolean>((resolve) => {
+    request({ method: "GET", hostname: "icanhazip.com" }, (res) => {
+      res.on("data", () => {});
+
+      res.on("end", () => {
+        resolve(res.statusCode === 200);
+      });
+    })
+      .on("error", () => {
+        resolve(false);
+      })
+      .end();
+  });
+};
 
 const CheckForUpdates = async () => {
   const updateText =
@@ -119,8 +135,7 @@ const CheckForUpdates = async () => {
 
   // even if cached once in a while it should get newest data
   if ((cachedVersion && Math.random() < 0.1) || cachedVersion === null) {
-    const isOnline = (await fetch("https://icanhazip.com")).status === 200;
-    if (!isOnline) return;
+    if (!(await isOnline())) return;
 
     const serverVersion = execSync("npm show @resultium/rcz version")
       .toString()