CI: add Ruby 2.7.1

For td-agent v4.0.0.

Exclude macOS because the latest macOS runner does not support
old Ruby versions.

Signed-off-by: Daijiro Fukuda <[email protected]>

Author: daipom

.github/workflows/main.yml

@@ -13,6 +13,11 @@ jobs:
       matrix:
         ruby: ['3.4', '3.3', '3.2']
         os: ['ubuntu-latest', 'macos-latest', 'windows-latest']
+        include:
+          - os: ubuntu-latest
+            ruby: 2.7.1
+          - os: windows-latest
+            ruby: 2.7.1
     runs-on: ${{ matrix.os }}
     name: Test with Ruby ${{ matrix.ruby }} on ${{ matrix.os }}
     steps:
@@ -29,7 +34,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['3.4', '3.3', '3.2']
+        ruby: ['3.4', '3.3', '3.2', '2.7.1']
         # macOS is excluded because of the difficulty in assuming a macOS shell behavior.
         os: ['ubuntu-latest', 'windows-latest']
         include:

fluent-tail_checker.gemspec

@@ -11,7 +11,6 @@ Gem::Specification.new do |spec|
   spec.summary = "summary" # TODO
   spec.description = "description" # TODO
   # spec.homepage = "TODO: Put your gem's website or public repo URL here."
-  spec.required_ruby_version = ">= 3.1.0"
 
   # spec.metadata["allowed_push_host"] = "TODO: Set to your gem server 'https://example.com'"