Use travis build matrix

Author: vgarvardt

.travis.yml

@@ -5,12 +5,13 @@ php:
   - '7.0'
   - '7.1'
 
+env:
+  - COMPOSER_UPDATE=
+  - COMPOSER_UPDATE=--prefer-lowest
+
 script:
-  - composer install -n
+  - composer update $COMPOSER_UPDATE -n
   - vendor/bin/php-cs-fixer fix --dry-run -v
-  - vendor/bin/phpunit
-  - rm -rf vendor
-  - composer update --prefer-lowest -n
   - vendor/bin/phpunit --coverage-clover=coverage.xml
 
 after_success:

src/Client/AbstractClient.php

@@ -33,7 +33,10 @@ abstract protected function getState();
     public function trackRequest(RequestInterface $request, Timer $timer, $success)
     {
         $bucket = new Bucket\HTTPRequest(
-            $this->httpRequestSection, $request, $success, $this->getHTTPMetricAlterCallback()
+            $this->httpRequestSection,
+            $request,
+            $success,
+            $this->getHTTPMetricAlterCallback()
         );
         $incrementer = $this->getIncrementer();