removed secret.rb, it's no longer needed

Jenkinsfile

@@ -53,7 +53,7 @@ pipeline {
             cp .env.rb /tmp/url-shortener/
             cp .ruby-version /tmp/url-shortener/
             cd /tmp/url-shortener
-            rm -rf features spec coverage db/*.db .git* Jenkinsfile *.html secret.rb
+            rm -rf features spec coverage db/*.db .git* Jenkinsfile *.html
             cd /tmp
             tar -czvf $ZIP_FILE url-shortener/
             mv /tmp/$ZIP_FILE $CUR_DIR/

secret.rb

@@ -1,2 +0,0 @@
-require 'securerandom'
-puts SecureRandom.base64(64).inspect()