Your old boss was a jerk and your former company treated you like garbage. You gave them years of your life and they rewarded you by unceremoniously giving you the axe just before bonus-time and days prior to being fully vested in your 401k. They’re horrible, we get it.
But even though all of that might be true, we recommend keeping it to yourself.
When your interviewer asks you why you left just bite your tongue and say something along the lines of "I'm grateful for all the opportunities I had there but in the end I wanted to work for a company with more opportunities in line with my career goals." Besides, bad-mouthing your former employer to your potential future employer just isn’t a very intelligent tactic. Take the high road and show them you're a class act instead of a mudslinger.