happy-2.0: dependencies

Dependencies for happy-2.0

happy	array base (<5) containers (>=0.4.2) happy-backend-glr (==2.0) happy-backend-lalr (==2.0) happy-codegen-common (==2.0) happy-frontend (==2.0) happy-grammar (==2.0) happy-tabular (==2.0) mtl (>=2.2.1)