chore: add gitignore and build configuration

.gitignore

@@ -0,0 +1,15 @@
+# runtime data stores
+*.pstore
+*.sqlite3
+
+# bundler / dependencies
+.bundle/
+vendor/bundle/
+
+# temp / logs
+tmp/
+*.log
+
+# os / editor / env
+.DS_Store
+.env

Rakefile

@@ -0,0 +1,9 @@
+task default: :test
+
+task :test do
+  sh 'ruby -Itest -Ilib test/run_all.rb'
+end
+
+task :demo do
+  sh 'ruby demo.rb'
+end