CNN  —  A shoe hurled into the air. A traveler pirouetting and somersaulting through the departure gate. The voice of Celine Dion reverberating across the terminal. It’s not a scene you often come across at the airport — or at least, it didn’t used to be. But on social media at least, dancing at an airport has become the travel trend du jour, with travelers across the world spinning through baggage claim, whirling through terminals and rolling through airport gates, garnering millions of online