write smart backup class
missing require
test if version is a string
write out spec for backup
Specced out names
fix name
better argument
comment what that method is for
define flag behavior
less nesting
implement more functionality into the model class
make failing test for date
try to parse the date
use ==
add tests for rest of model class
remove retention calculator model
retention calculator spec
stub out time#now
stick to speccing
retention calculator test with strings