Add mini test example

imag-ruby/test/test_store_id_load.rb

@@ -0,0 +1,11 @@
+#!/usr/bin/env ruby
+
+require 'fiddle'
+
+lib = Fiddle::dlopen './target/debug/libimag_ruby.so'
+Fiddle::Function::new(lib['imag_ruby_initialize'], [], Fiddle::TYPE_VOIDP).call
+
+works = (not RStoreId.new_baseless("test").nil?)
+
+puts "Works: #{works}"
+