Use local phpunit

Gruntfile.js

@@ -53,6 +53,12 @@ module.exports = function (grunt) {
                 }
             },
             phpunit: {
+                options: {
+                    bin: './vendor/bin/phpunit',
+                    stopOnError: true,
+                    stopOnFailure: true,
+                    followOutput: true
+                },
                 classes: {
                     dir: 'tests/'
                 }

composer.json

@@ -18,7 +18,8 @@
 	},
 	"require-dev": {
 		"symfony/var-dumper": "~3.1.0",
-		"squizlabs/php_codesniffer": "~2.6.2"
+		"squizlabs/php_codesniffer": "~2.6.2",
+		"phpunit/phpunit": "~5.4.8"
 	},
 	"extra": {
 		"paas": {