Default branch rename

Helps with whatwg/meta#174.

.github/workflows/build.yaml

@@ -2,10 +2,10 @@ name: Build
 on:
   pull_request:
     branches:
-    - master
+    - main
   push:
     branches:
-    - master
+    - main
 jobs:
   build:
     name: Build
@@ -34,13 +34,13 @@ jobs:
         mkdir output
         bash ci-build/docker-run.sh "$GITHUB_WORKSPACE/html" output
     - name: Docker login
-      if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/master' }}
+      if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
       uses: docker/login-action@v1
       with:
         username: ${{ secrets.DOCKER_HUB_USERNAME }}
         password: ${{ secrets.DOCKER_HUB_TOKEN }}
     - name: Docker push
-      if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/master' }}
+      if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
       run: |
         docker tag "$IMAGE_NAME" "$IMAGE_NAME:$GITHUB_SHA"
         docker tag "$IMAGE_NAME" "$IMAGE_NAME:latest"

build.sh

@@ -191,7 +191,7 @@ function checkHTMLBuildIsUpToDate {
   fi
   # TODO: `git remote get-url origin` is nicer, but new in Git 2.7.
   ORIGIN_URL=$(git config --get remote.origin.url)
-  GIT_FETCH_ARGS+=( "$ORIGIN_URL" master)
+  GIT_FETCH_ARGS+=( "$ORIGIN_URL" main)
   git fetch "${GIT_FETCH_ARGS[@]}"
   NEW_COMMITS=$(git rev-list --count HEAD..FETCH_HEAD)
   if [[ $NEW_COMMITS != "0" ]]; then
@@ -203,7 +203,7 @@ function checkHTMLBuildIsUpToDate {
     echo
     echo "To update, run this command:"
     echo
-    echo "  git pull --rebase origin master"
+    echo "  git pull --rebase origin main"
     echo
     echo "This check can be bypassed with the --no-update option."
     exit 1