Added satooshi/php-coveralls to composer.json [ci skip]

composer.json

@@ -8,7 +8,8 @@
 		"php": ">=5.3.0"
 	},
 	"require-dev": {
-		"mockery/mockery": ">=0.7.2"
+		"mockery/mockery": ">=0.7.2",
+		"satooshi/php-coveralls": "dev-master"
 	},
 	"repositories": [
 		{
@@ -46,4 +47,4 @@
 		"zetacomponents/database": "A PDO implementation of the storage classes",
 		"doctrine/dbal": "A Doctrine/DBAL implementation of the storage classes"
 	}
-}
+}