Remove --color switch from phpunit command.

Colors are already enabled in the phpunit.xml.dist file so the command line switch shouldn't be required.

composer.json

@@ -78,7 +78,7 @@
         ],
         "cs-check": "phpcs --colors -p ./src ./tests",
         "cs-fix": "phpcbf --colors ./src ./tests",
-        "test": "phpunit --colors=always",
-        "test-coverage": "phpunit --colors=always --coverage-clover=clover.xml"
+        "test": "phpunit",
+        "test-coverage": "phpunit --coverage-clover=clover.xml"
     }
 }