Xeta 3.1.0 released

Bugs Fixed :

• Fixed a bug in the AJAX call for cookies tracking. Ref #222

Changes :

• Removed PHP 5.5 support. (Since CakePHP 3.4 is now >= 5.6) Ref c39a686
• Updated the code to CakePHP 3.4. Ref #215
• Optimized i18Format to use the new TimeHelper. Ref #224

New Features :

• Added a Poll system to the Blog articles. Ref #210, #220
• Added a new CSS style to the Home page. Ref #217