covenant which goes with the land as being annexed to the estate and which cannot be separated from the land and transferred without it. A covenant is said to run with the land when not only the original parties or their representatives but each successive owner of the land will be entitled to its benefit or be liable (as the case may be) to its obligation. Or in other words it is so called when either the liability to perform it or the right to take advantage of it passes to the assignee of the land.