Magic of Crystal and Amber (Part 1) - SD Ruby Meetup December 2017

[loscuchis]

Great presentation! One correction: Manas is in Argentina. And maybe when you do `crystal program.cr` and an error appears, it's not clear why that's a compile-time error vs. a runtime error (you'd get more or less the same output in Ruby). You could use `crystal build program.cr` to show that, and then show that no `program` file was generated.