Added ATS to list of languages.

ATS is a statically typed programming language that unifies implementation with formal specification. It is equipped with a highly expressive type system rooted in the framework Applied Type System, which gives the language its name. In particular, both dependent types and linear types are available in ATS.

Language Website:
http://www.ats-lang.org

Latest Compiler:
http://github.com/githwxi/ATS-Postiats