How to properly setup Datamapper with SQLite on Windows

I have Windows 7 x64 and Ruby 2.2 x86. I have the following Ruby code:

require 'data_mapper'
DataMapper.setup(:default, "http://sqlite3#{File.expand_path(File.dirname(__FILE__))}/db.sqlite")
DataMapper.finalize

When I run it I just have "Process finished with exit code 0" and nothing happens. No 'db.sqlite' creates anywhere. I've tried to reinstall all related to DataMapper gems but nothing seem to work. My SQLite dll version is recommended by do_sqlite3 gem (which is 3071700). Please help!