Merge pull request #29 from SpringMT/update-zstd-for-v1.4.9

feat: Update zstd to v1.4.9

.github/workflows/ruby.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['2.6', '2.7', '3.0']
+        ruby-version: ['2.5', '2.6', '2.7', '3.0']
 
     steps:
     - uses: actions/checkout@v2
@@ -29,5 +29,7 @@ jobs:
         bundler-cache: true # runs 'bundle install' and caches installed gems automatically
     - name: Install dependencies
       run: bundle install
+    - name: Compile
+      run: bundle exec rake compile
     - name: Run tests
       run: bundle exec rspec

README.md

@@ -1,5 +1,5 @@
 [![Gem Version](https://badge.fury.io/rb/zstd-ruby.svg)](https://badge.fury.io/rb/zstd-ruby)
-[![Build Status](https://travis-ci.org/SpringMT/zstd-ruby.svg?branch=master)](https://travis-ci.org/SpringMT/zstd-ruby)
+![Build Status](https://github.com/SpringMT/zstd-ruby/actions/workflows/ruby.yml/badge.svg?branch=master)
 
 # zstd-ruby
 
@@ -10,7 +10,7 @@ See https://github.com/facebook/zstd
 Fork from https://github.com/jarredholman/ruby-zstd.
 
 ## Zstd version
-v1.4.5 (https://github.com/facebook/zstd/tree/v1.4.5)
+v1.4.9 (https://github.com/facebook/zstd/tree/v1.4.9)
 
 ## Installation