cast.from_env() takes an environment variable name instead of the
string as the first argument and does the obvious thing. It also
takes a default and saves the conversion in case the environment
variable doesn't exist.
Signed-off-by: Jan Lindemann <jan@janware.com>
Using cast.from_str('blah') seems more logical than cast.cast_str(),
so add that alias and see how it fares.
Signed-off-by: Jan Lindemann <jan@janware.com>
