Update stylish-haskell to 0.11.

iphydf · iphydf · commit ba937a2318be · 2020-03-06T20:41:54.000Z
See haskell/stylish-haskell#265. Without this, stylish-haskell deletes many comments and is generally broken.
diff --git a/.gitignore b/.gitignore
@@ -1 +1,2 @@
 /.stack-work
+/stack.yaml.lock
diff --git a/stack.yaml b/stack.yaml
@@ -1,3 +1,5 @@
 ---
 packages: []
 resolver: lts-15.2
+extra-deps:
+  - stylish-haskell-0.11.0.0
