Problems when running interactive.sh script

[jwross24]

I had a couple errors occur while running the interactive.sh script that I might be able to address.

1. When creating the GPG Agent config, I got an error saying the ~/.gnupg directory did not exist. This might be my own issue due to not running the brew install with sudo, but I suggest adding a mkdir -p ~/.gnupg in the script to catch this error.
2. When installing the ruby plugin with asdf, this line should reference ruby, not latest as the plugin to install.

I created a pull request to help address these errors, so let me know if you think these are valid.