fixes #3; fixes macOS CI (#4)

Author: ringabout

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
             builder: ubuntu-20.04
           - target:
               os: macos
-            builder: macos-10.15
+            builder: macos-11
           - target:
               os: windows
             builder: windows-2019
@@ -126,4 +126,4 @@ jobs:
           build_dir: htmlparser/htmldocs
           target_branch: gh-pages
         env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}