Haskelloids does not build with ghc 8.4.4 and 8.6.1

.travis.yml

@@ -9,11 +9,9 @@ ghc:
   - "7.10.3"
   - "8.0.2"
   - "8.2.2"
-
-# 8.4.4 and 8.6.1 currently do not build.
-# See https://github.com/keera-studios/Haskelloids/issues/30
-#  - "8.4.4" 
-#  - "8.6.1"
+  - "8.4.4" 
+  - "8.6.5"
+  - "8.8.4"
 
 before_install:
   - travis_retry sudo apt-get update

Haskelloids.cabal

@@ -75,7 +75,7 @@ Executable Haskelloids
     matrix      == 0.3.*,
     vector      == 0.12.*,
     HGL         == 3.*,
-    Yampa       == 0.10.*
+    Yampa       == 0.13.*
 
   -- Modules not exported by this package.
   -- Other-modules:       

stack.yaml

@@ -18,7 +18,7 @@
 #
 # resolver: ./custom-snapshot.yaml
 # resolver: https://example.com/snapshots/2018-01-01.yaml
-resolver: lts-11.13
+resolver: lts-16.17
 
 # User packages to be built.
 # Various formats can be used as shown in the example below.
@@ -39,7 +39,8 @@ packages:
 # using the same syntax as the packages field.
 # (e.g., acme-missiles-0.3)
 extra-deps:
-- HGL-3.2.3.1
+- HGL-3.2.3.2
+- Yampa-0.13.1
 
 # Override default flag values for local packages and extra-deps
 # flags: {}

stack.yaml.lock

@@ -0,0 +1,26 @@
+# 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: HGL-3.2.3.2@sha256:35922953927a1d68845c6446ff69952c5303412cee3e3a2d95c1449132f90eef,2116
+    pantry-tree:
+      size: 2189
+      sha256: 746fa311ed17c9a300423cc8f54904a58fc5df99886d8fc2dacabf13c642125d
+  original:
+    hackage: HGL-3.2.3.2
+- completed:
+    hackage: Yampa-0.13.1@sha256:4612a2646c27bcd3ac55c90dbc34249303e28aa5b3bc3e0c6fa9ce58b889843c,5436
+    pantry-tree:
+      size: 4039
+      sha256: 2ebdfafc0143a66132e1f790fc3909c93654ee89fbe468574c5c2a36070dc6b3
+  original:
+    hackage: Yampa-0.13.1
+snapshots:
+- completed:
+    size: 532386
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/16/17.yaml
+    sha256: d3ee1ae797cf63189c95cf27f00700304946c5cb3c1e6a82001cd6584a221e1b
+  original: lts-16.17