Add examples/batch.rb script to demo batch geocoding with the async gem (#29)

* Add examples/batch.rb script to demo batch geocoding with the async gem

* Stop testing Ruby 3.0

Ruby 3.0 is end of life and the async gem is not compatible with it.

Author: sbscully

.github/workflows/build.yml

@@ -13,7 +13,7 @@ jobs:
       matrix:
         os: [ubuntu-latest]
         # https://www.ruby-lang.org/en/downloads/branches/
-        ruby: ["3.0", "3.1", "3.2", "3.3"]
+        ruby: ["3.1", "3.2", "3.3"]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4

Gemfile

@@ -3,6 +3,7 @@ source 'https://rubygems.org'
 gemspec
 
 group :development, :test do
+  gem 'async'
   gem 'rake'
   gem 'rspec'
   gem 'rubocop'

Gemfile.lock

@@ -9,12 +9,25 @@ GEM
     addressable (2.8.6)
       public_suffix (>= 2.0.2, < 6.0)
     ast (2.4.2)
+    async (2.19.0)
+      console (~> 1.29)
+      fiber-annotation
+      io-event (~> 1.6, >= 1.6.5)
     bigdecimal (3.1.8)
+    console (1.29.0)
+      fiber-annotation
+      fiber-local (~> 1.1)
+      json
     crack (1.0.0)
       bigdecimal
       rexml
     diff-lcs (1.5.1)
+    fiber-annotation (0.2.0)
+    fiber-local (1.1.0)
+      fiber-storage
+    fiber-storage (1.0.0)
     hashdiff (1.1.0)
+    io-event (1.7.3)
     json (2.7.2)
     language_server-protocol (3.17.0.3)
     parallel (1.25.1)
@@ -78,6 +91,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  async
   opencage-geocoder!
   rake
   rspec