Add CLI

[alexarchambault]

Fixes https://github.com/dirs-dev/directories-jvm/issues/32.

Use like

$ directories Foo
cache:      /Users/alexandre/Library/Caches/Foo
config:     /Users/alexandre/Library/Application Support/Foo
data:       /Users/alexandre/Library/Application Support/Foo
local data: /Users/alexandre/Library/Application Support/Foo
preference: /Users/alexandre/Library/Preferences/Foo
runtime:    null
$ directories Foo --cache
/Users/alexandre/Library/Caches/Foo