checkout: Dir.mktmpdir is actually in tempfile
treeaed091a5c097046454f1dfa5c0ba12d4cf549fd8
drwxr-xr-x - checkout_git_repository
-rw-r--r-- 2048 concept.txt
drwxr-xr-x - door
drwxr-xr-x - etc
drwxr-xr-x - init_card
drwxr-xr-x - lib
-rw-r--r-- 356 opencorn.cfg.example
drwxr-xr-x - revoke