Add support for PHP 7.3

Author: GhaziTriki

.travis.yml

@@ -7,6 +7,7 @@ php:
   - 7.0
   - 7.1
   - 7.2
+  - 7.3
   - hhvm
   - nightly
 

README.md

@@ -12,15 +12,13 @@ The official and easy to use **BigBlueButton API for PHP**, makes easy for devel
 [![Coverage Status](https://coveralls.io/repos/github/bigbluebutton/bigbluebutton-api-php/badge.svg?branch=master)](https://coveralls.io/github/bigbluebutton/bigbluebutton-api-php?branch=master)
 [![Scrutinizer Code Quality](https://scrutinizer-ci.com/g/bigbluebutton/bigbluebutton-api-php/badges/quality-score.png?b=master)](https://scrutinizer-ci.com/g/bigbluebutton/bigbluebutton-api-php/?branch=master)
 
-
 [![@bigbluebutton on Twitter](https://img.shields.io/badge/twitter-%40bigbluebutton-blue.svg?style=flat)](https://twitter.com/bigbluebutton)
 ![Website](https://img.shields.io/website-up-down-green-red/http/bigbluebutton.org.svg?label=BigBlueButton.org)
 
-[![PHP 5.4](https://img.shields.io/badge/php-5.4-f33.svg?style=flat-square)](https://php.net/)
 [![PHP 5.5](https://img.shields.io/badge/php-5.5-f33.svg?style=flat-square)](https://php.net/)
-[![PHP 5.6](https://img.shields.io/badge/php-5.6-f93.svg?style=flat-square)](https://php.net/)
-[![PHP 7](https://img.shields.io/badge/php-7-f93.svg?style=flat-square)](https://php.net/)
-[![PHP 7.1](https://img.shields.io/badge/php-7.1-9c9.svg?style=flat-square)](https://php.net/)
+[![PHP 5.6](https://img.shields.io/badge/php-5.6-f33.svg?style=flat-square)](https://php.net/)
+[![PHP 7.0](https://img.shields.io/badge/php-7.0-f33.svg?style=flat-square)](https://php.net/)
+[![PHP 7.1](https://img.shields.io/badge/php-7.1-f93.svg?style=flat-square)](https://php.net/)
 [![PHP 7.2](https://img.shields.io/badge/php-7.2-9c9.svg?style=flat-square)](https://php.net/)
 [![PHP 7.3](https://img.shields.io/badge/php-7.3-9c9.svg?style=flat-square)](https://php.net/)