Laravel 5.6 updates

Travis config update

Removed HHVM script as Laravel no longer support HHVM after releasing 5.3

vendor/phpunit/php-timer/README.md

@@ -1,6 +1,6 @@
 [![Build Status](https://travis-ci.org/sebastianbergmann/php-timer.svg?branch=master)](https://travis-ci.org/sebastianbergmann/php-timer)
 
-# PHP_Timer
+# phpunit/php-timer
 
 Utility class for timing things, factored out of PHPUnit into a stand-alone component.
 
@@ -19,14 +19,16 @@ If you only need this library during development, for instance to run your proje
 ### Basic Timing
 
 ```php
-PHP_Timer::start();
+use SebastianBergmann\Timer\Timer;
+
+Timer::start();
 
 // ...
 
-$time = PHP_Timer::stop();
+$time = Timer::stop();
 var_dump($time);
 
-print PHP_Timer::secondsToTimeString($time);
+print Timer::secondsToTimeString($time);
 ```
 
 The code above yields the output below:
@@ -37,7 +39,9 @@ The code above yields the output below:
 ### Resource Consumption Since PHP Startup
 
 ```php
-print PHP_Timer::resourceUsage();
+use SebastianBergmann\Timer\Timer;
+
+print Timer::resourceUsage();
 ```
 
 The code above yields the output below: