remove outdated comment

lib/main.js

@@ -20,7 +20,6 @@ function run() {
             if (!util_1.isTag(config.github_ref)) {
                 throw new Error(`⚠️ GitHub Releases requires a tag`);
             }
-            // todo: validate github_ref is a tag
             const gh = new github_1.GitHub(config.github_token);
             let rel = yield github_2.release(config, gh);
             if (config.input_files) {