The Boston Seaport district isn't short on much. There's plenty of bars, high-end restaurants, luxury condos, and businesses popping up daily. But what about delicious, fresh food options that won't break the bank? Cue Shake Shack, home of ridiculously delicious burgers, fries, sandwiches and 'concrete' shakes to fill the void. Recently opened as their 100th Shack, the Seaport location (77 Seaport Blvd) is situated at a perfect spot just next to a nearly completed CVS and Sta