Updated to PHPUnit 6 and had to remove humbug in the progress

Author: WyriHaximus

Makefile

@@ -16,8 +16,5 @@ cs:
 unit:
 	composer unit
 
-mutation:
-	composer mutation
-
 ci-coverage: init
 	composer ci-coverage

composer.json

@@ -17,8 +17,7 @@
     },
     "require-dev": {
         "guzzlehttp/psr7": "^1.3",
-        "humbug/humbug": "1.0.0-alpha2",
-        "phpunit/phpunit": "^5.6",
+        "phpunit/phpunit": "^6.0",
         "squizlabs/php_codesniffer": "^2.6"
     },
     "autoload": {
@@ -47,14 +46,9 @@
             "@ensure-installed",
             "phpunit --colors=always -c phpunit.xml.dist --coverage-text --coverage-html covHtml --coverage-clover ./build/logs/clover.xml"
         ],
-        "mutation": [
-            "@ensure-installed",
-            "if [ `php -m | grep xdebug | wc -l` -gt 0 ]; then humbug --ansi --incremental; fi"
-        ],
         "qa-all": [
             "@cs",
-            "@unit",
-            "@mutation"
+            "@unit"
         ],
         "qa-windows": [
             "@cs",