[nix] upgrade sha256 for nix/easy-ps.nix and nix/pinned.nix

nix/easy-ps.nix

@@ -6,7 +6,7 @@ import
       owner = "justinwoo";
       repo = "easy-purescript-nix";
       rev = "7ebddd8613cf6736dbecef9fce4c32f2a104ef82";
-      sha256 = "0lmkppidmhnayv0919990ifdd61f9d23dzjzr8amz7hjgc74yxs0";
+      sha256 = "1g1hlybld298kimd1varvwiflpb0k7sdqlmcqha3kswjvy5z4k6k";
     }
   ) {
   inherit pkgs;

nix/pinned.nix

 import (
   builtins.fetchTarball {
     url = "https://github.com/NixOS/nixpkgs/archive/20.03.tar.gz";
-    sha256 = "07n91k3d9i9pym8npsszha9mnvg4d1r0l0ldnhk4g8sx15vv1br5";
+    sha256 = "0182ys095dfx02vl2a20j1hz92dx3mfgz2a6fhn31bqlp1wa8hlq";
   }
 )