Update to latest possible LTS and packages

hakyll-site.cabal

@@ -6,6 +6,6 @@ cabal-version:      >= 1.10
 executable site
   main-is:          site.hs
   build-depends:    base == 4.*
-                  , hakyll == 4.12.*
+                  , hakyll == 4.15.*
   ghc-options:      -threaded
   default-language: Haskell2010

stack.yaml

@@ -15,7 +15,7 @@
 # resolver:
 #  name: custom-snapshot
 #  location: "./custom-snapshot.yaml"
-resolver: lts-13.0
+resolver: lts-17.5
 
 # User packages to be built.
 # Various formats can be used as shown in the example below.
@@ -40,14 +40,14 @@ packages:
 # Dependency packages to be pulled from upstream that are not in the resolver
 # (e.g., acme-missiles-0.3)
 extra-deps:
-    - ipynb-0.1
+    - ipynb-0.1.0.1
     - lrucache-1.2.0.1
-    - pandoc-2.7
-    - pandoc-citeproc-0.16.2
-    - skylighting-0.7.7
-    - skylighting-core-0.7.7
-    - texmath-0.11.2.2
-    - hakyll-4.12.5.2
+    - pandoc-2.11.4
+    - citeproc-0.3.0.8
+    - skylighting-0.10.4
+    - skylighting-core-0.10.4
+    - texmath-0.12.1.1
+    - hakyll-4.15.1.0
 
 # Override default flag values for local packages and extra-deps
 flags: {}