add dependency licenses to NOTICE

.github/workflows/notice.yaml

+name: Notice
+on:
+  push:
+    paths:
+      - stack.yaml
+      - stack.yaml.lock
+      - sv2v.cabal
+      - notice.sh
+      - NOTICE
+jobs:
+  notice:
+    runs-on: macOS-latest
+    steps:
+      - uses: actions/checkout@v1
+      - name: Install Haskell Stack
+        run: brew install haskell-stack
+      - name: Regenerate NOTICE
+        run: ./notice.sh > NOTICE
+      - name: Validate NOTICE
+        run: |
+          if [ -n "`git status --porcelain`" ]; then
+            echo "Notice differs!"
+            PAGER= git diff
+            exit 1
+          fi

notice.sh

+#!/bin/bash
+
+dependencies=`stack ls dependencies \
+    | sed -e 's/ /-/' \
+    | grep -v "^sv2v-[0-9\.]\+\$" \
+    | grep -v "^rts-1\.0\$" \
+    `
+
+for dependency in `echo "$dependencies"`; do
+    license_url="https://hackage.haskell.org/package/$dependency/src/LICENSE"
+
+    echo "================================================================================"
+    echo "Dependency: $dependency"
+    echo "================================================================================"
+    echo ""
+    curl "$license_url" 2> /dev/null | sed -e "s/^/  /"
+    echo ""
+done

sv2v.cabal

@@ -10,6 +10,7 @@ author: Zachary Snow <zach@zachjs.com>, Tom Hawkins <tomahawkins@gmail.com>
 maintainer: Zachary Snow <zach@zachjs.com>
 license: BSD3
 license-file: LICENSE
+license-files: NOTICE
 homepage: https://github.com/zachjs/sv2v
 
 build-type: Simple