Adds travis build support for PHP 7.3.

Author: allebb

.travis.yml

@@ -9,7 +9,8 @@ php:
   - 7.0
   - 7.1
   - 7.2
-  - hhvm
+  - 7.3
+  - nightly
 
 sudo: false
 

README.md

@@ -15,7 +15,7 @@ Requirements
 
 * PHP >= 5.4.0
 
-This library is unit tested against PHP 5.4, 5.5, 5.6, 7.0 and HHVM!
+This library is unit tested against PHP 5.4, 5.5, 5.6, 7.0, 7.1, 7.2, 7.3 and the PHP nightly builds!
 
 License
 -------
@@ -48,7 +48,7 @@ Tests and coverage
 
 This library is fully unit tested using [PHPUnit](https://phpunit.de/).
 
-I use [TravisCI](https://travis-ci.org/) for continuous integration, which triggers tests for PHP 5.4, 5.5, 5.6, 7.0 and HHVM every time a commit is pushed.
+I use [TravisCI](https://travis-ci.org/) for continuous integration, which triggers tests for PHP 5.4, 5.5, 5.6, 7.0, 7.1, 7.2, 7.3 and the PHP nightly build every time a commit is pushed.
 
 If you wish to run the tests yourself you should run the following: