Reorganize Travis deploy stages (#405)

Heroku is now deployed along with the other platforms, since it
doesn't directly depend on any of them. Bazel is deployed after
everything else, because it depends on npm deploying successfully.

.travis.yml

@@ -70,7 +70,7 @@ script: tool/travis/test.sh
 jobs:
   include:
   # Deploy to GitHub.
-  - stage: deploy
+  - stage: deploy 1
     if: &deploy-if
       (type IN (push, api)) AND (repo = sass/dart-sass) AND tag =~ ^\d+\.\d+\.\d+([+-].*)?$
     env: &github-env
@@ -126,16 +126,6 @@ jobs:
       skip_cleanup: true
       on: {tags: true}
 
-  # Deploy to Bazel.
-  - if: *deploy-if
-    env: *github-env
-    script: skip
-    deploy:
-      provider: script
-      script: pub run grinder update-bazel
-      skip_cleanup: true
-      on: {tags: true}
-
   # Deploy to Chocolatey.
   - if: *deploy-if
     env:
@@ -148,9 +138,8 @@ jobs:
       skip_cleanup: true
       on: {tags: true}
 
-  # Redeploy sass-lang.com when a build succeeds.
-  - stage: site
-    if: *deploy-if
+  # Redeploy sass-lang.com.
+  - if: *deploy-if
     env:
       # HEROKU_TOKEN="..."
       - secure: "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"
@@ -162,3 +151,15 @@ jobs:
       # private endpoint instead.
       script: tool/travis/deploy/heroku.sh
       on: {tags: true}
+
+  # Deploy to Bazel. This is in a separate deploy stage because it needs to
+  # install the npm package.
+  - stage: deploy 2
+    if: *deploy-if
+    env: *github-env
+    script: skip
+    deploy:
+      provider: script
+      script: pub run grinder update-bazel
+      skip_cleanup: true
+      on: {tags: true}