modify enforcer output a bit

Author: php-coder

Dangerfile

@@ -275,7 +275,7 @@ else
 	unless errors.empty?
 		error_msgs = errors.join("\n")
 		fail("maven-enforcer-plugin reported about errors. Please, fix them. "\
-			"Here is its output:\n```#{error_msgs}\n```")
+			"Here is its output:\n```\n#{error_msgs}\n```")
 	end
 end