updated .travis.yml to test with beta.4

.travis.yml

@@ -33,7 +33,7 @@ before_install:
 before_script:
   - echo 'extension = memcached.so' >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini
   - shopt -s extglob dotglob && mkdir aauth_temp && mv !(aauth_temp) aauth_temp
-  - git clone https://github.com/codeigniter4/CodeIgniter4.git CodeIgniter4 -b v4.0.0-beta.1
+  - git clone https://github.com/codeigniter4/CodeIgniter4.git CodeIgniter4 -b v4.0.0-beta.4
   - cp -r aauth_temp/* CodeIgniter4 && cd CodeIgniter4 && cp _travis/env .env
   - composer install --prefer-source
   - composer require spomky-labs/otphp --prefer-source