Update package-sets tag to psc-0.12.5-20190508 (#190)

Author: pacchettibotti

templates/packages.dhall

@@ -109,10 +109,10 @@ let additions =
 -}
 
 let mkPackage =
-      https://raw.githubusercontent.com/purescript/package-sets/psc-0.12.5-20190504/src/mkPackage.dhall sha256:0b197efa1d397ace6eb46b243ff2d73a3da5638d8d0ac8473e8e4a8fc528cf57
+      https://raw.githubusercontent.com/purescript/package-sets/psc-0.12.5-20190508/src/mkPackage.dhall sha256:0b197efa1d397ace6eb46b243ff2d73a3da5638d8d0ac8473e8e4a8fc528cf57
 
 let upstream =
-      https://raw.githubusercontent.com/purescript/package-sets/psc-0.12.5-20190504/src/packages.dhall sha256:b0c8ec260863f07103b1982b0bbe90601eb11bd8eee45d5c4fe6d633b1b44bf4
+      https://raw.githubusercontent.com/purescript/package-sets/psc-0.12.5-20190508/src/packages.dhall sha256:8ef3a6d6d123e05933997426da68ef07289e1cbbdd2a844b5d10c9159deef65a
 
 let overrides = {=}