Update for GHC 8.6.5

Also remove shell.nix

plate.cabal

@@ -54,6 +54,8 @@ test-suite test
     test
   main-is: Test.hs
   other-modules:
+    Test.ReadmeExamples
+    Test.Prelude
     Test.SimplePlate
     Test.Validation
   default-language: Haskell2010

src/Plate/Validation.hs

@@ -1,7 +1,7 @@
 
 module Plate.Validation where
 
-import           Plate.Prelude hiding (evaluate, exp)
+import           Plate.Prelude hiding (evaluate, exp, replace)
 
 import qualified Data.HashMap.Strict as HM
 

src/Plate/Value.hs

@@ -6,7 +6,6 @@ import           Plate.Prelude hiding (evaluate, exp)
 import           Control.Monad (fail)
 import           Data.Aeson
 import           Data.Aeson.Types (Parser)
-import           Data.Hashable
 import qualified Data.HashMap.Strict as HM
 import           Data.HashSet (HashSet)
 import qualified Data.HashSet as HashSet

stack.yaml

@@ -1,6 +1,3 @@
-resolver: lts-8.10
+resolver: lts-14.18
 extra-deps:
-  - aeson-1.1.1.0
-nix:
-  enable: true
-  shell-file: shell.nix
+  - aeson-1.4.6.0 # Important enough to lock down

stack.yaml.lock

@@ -0,0 +1,19 @@
+# This file was autogenerated by Stack.
+# You should not edit this file by hand.
+# For more information, please see the documentation at:
+#   https://docs.haskellstack.org/en/stable/lock_files
+
+packages:
+- completed:
+    hackage: aeson-1.4.6.0@sha256:560575b008a23960403a128331f0e59594786b5cd19a35be0cd74b9a7257958e,6980
+    pantry-tree:
+      size: 40193
+      sha256: 5769473440ae594ae8679dde9fe12b6d00a49264a9dd8962a53ff3ae5740d7a5
+  original:
+    hackage: aeson-1.4.6.0
+snapshots:
+- completed:
+    size: 524789
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/14/18.yaml
+    sha256: 646be71223e08234131c6989912e6011e01b9767bc447b6d466a35e14360bdf2
+  original: lts-14.18