Copy a File to rails project folder using gem

I am in the middle of developing a gem for rails and i stuck with this issue. My logic is I have a gem created, and the gem installed to my local machine. What I need is when I type gem_name --install, there is a file called test.rb should be copied to inside a rails project/ config/initializers/. this is currently placed in a folder in my gem. i have tried

Dir.pwd

but it is not give me results as expected.Please find a solution for me and TIA..