singletons-2.5: dependencies

Dependencies for singletons-2.5

library	base (>=4.12 && <4.13) containers (>=0.5) ghc-boot-th mtl (>=2.2.1 && <2.3) pretty syb (>=0.4) template-haskell text (>=1.2) th-desugar (>=1.9 && <1.10) transformers (>=0.5.2)