Update update.js to use signed tags

Author: giggio

update.js

@@ -26,7 +26,7 @@ const writeUpdate = (version) => {
   const updated = helper.replace(regex, `${versionExport} = '${version}';`);
   fs.writeFileSync('./lib/chromedriver.js', updated, 'utf8');
   const packageVersion = `${version.slice(0, 2)}.0.0`;
-  execSync(`npm version ${packageVersion} --git-tag-version=false && git add . && git commit -m "Bump version to ${packageVersion}" && git tag ${packageVersion}`);
+  execSync(`npm version ${packageVersion} --git-tag-version=false && git add . && git commit -m "Bump version to ${packageVersion}" && git tag -s ${packageVersion} -m ${packageVersion}`);
 };
 
 getLatest((version) => {