Install pip and gh in our docker builds. (#87)

Author: cjyar

.github/workflows/publish.yaml

@@ -82,7 +82,8 @@ jobs:
           - '14'
           - '16'
     steps:
-      - run: apk add build-base git python3 wget
+      - run: apk add build-base git python3 wget py3-pip
+      - run: pip install gh
       - uses: actions/checkout@v2
         with:
           ref: ${{ github.event.release.tag_name }}