* Implement info command
* Remove duplicate and unneeded BATS tests from `main_test.go`
* remove download dir for plugin when removing plugin
* update plugins.Add function so downloads directory is created
* rename commands package to cmd
* add go-ini as a dependency
* write code to parse asdfrc file into Settings struct
* add go-envconfig as a dependency
* add go-homedir as a dependency
* implement first version of LoadConfig function to load environment variables into Config struct
