downloader: add support for GH_TOKEN for https://api.github.com/

Author: kou

.github/workflows/test.yml

@@ -63,5 +63,7 @@ jobs:
         run: |
           bundle install
       - name: Test
+        env:
+          GH_TOKEN: ${{ github.token }}
         run: |
           bundle exec rake

lib/datasets/downloader.rb

@@ -168,6 +168,12 @@ def download(output_path, &block)
         else
           request = Net::HTTP::Get.new(path, headers)
         end
+        if url.scheme == "https" and url.host == "api.github.com"
+          gh_token = ENV["GH_TOKEN"]
+          if gh_token
+            headers = headers.merge("Authorization" => "Bearer #{gh_token}")
+          end
+        end
         http.request(request) do |response|
           case response
           when Net::HTTPSuccess, Net::HTTPPartialContent