dev-cmd/tap-new: Set up GitHub Actions CI instead of Azure

- We recently removed Azure as a supported CI provider
  (Homebrew/homebrew-test-bot PR 325), so `brew test-bot` won't run on
  Azure any more.
- Homebrew CI is moving towards GitHub Actions as the standard.

Library/Homebrew/dev-cmd/tap-new.rb

@@ -51,24 +51,31 @@ module Homebrew
     MARKDOWN
     write_path(tap, "README.md", readme)
 
-    azure = <<~YAML
+    actions = <<~YAML
+      name: brew test-bot
+      on:
+        push:
+          branches: master
+        pull_request: []
       jobs:
-      - job: macOS
-        pool:
-          vmImage: macOS-10.14
-        steps:
-          - bash: |
-              set -e
-              sudo xcode-select --switch /Applications/Xcode_10.2.1.app/Contents/Developer
-              brew update
-              HOMEBREW_TAP_DIR="/usr/local/Homebrew/Library/Taps/#{tap.full_name}"
-              mkdir -p "$HOMEBREW_TAP_DIR"
-              rm -rf "$HOMEBREW_TAP_DIR"
-              ln -s "$PWD" "$HOMEBREW_TAP_DIR"
-              brew test-bot
-            displayName: Run brew test-bot
+        test-bot:
+          runs-on: macos-latest
+          steps:
+            - name: Set up Git repository
+              uses: actions/checkout@v2
+            - name: Run brew test-bot
+              run: |
+                set -e
+                brew update
+                HOMEBREW_TAP_DIR="/usr/local/Homebrew/Library/Taps/#{tap.full_name}"
+                mkdir -p "$HOMEBREW_TAP_DIR"
+                rm -rf "$HOMEBREW_TAP_DIR"
+                ln -s "$PWD" "$HOMEBREW_TAP_DIR"
+                brew test-bot
     YAML
-    write_path(tap, "azure-pipelines.yml", azure)
+
+    (tap.path/".github/workflows").mkpath
+    write_path(tap, ".github/workflows/main.yml", actions)
     ohai "Created #{tap}"
     puts tap.path.to_s
   end

Library/Homebrew/test/dev-cmd/tap-new_spec.rb

@@ -7,12 +7,13 @@ describe "Homebrew.tap_new_args" do
 end
 
 describe "brew tap-new", :integration_test do
-  it "initializes a new Tap with a ReadMe file" do
+  it "initializes a new Tap with a ReadMe file and GitHub Actions CI" do
     expect { brew "tap-new", "homebrew/foo", "--verbose" }
       .to be_a_success
       .and output(%r{homebrew/foo}).to_stdout
       .and not_to_output.to_stderr
 
     expect(HOMEBREW_LIBRARY/"Taps/homebrew/homebrew-foo/README.md").to exist
+    expect(HOMEBREW_LIBRARY/"Taps/homebrew/homebrew-foo/.github/workflows/main.yml").to exist
   end
 end