Memoized the result of target invocation
Memoized the result of target invocation

For a current makescript I was unable to use promises as the task had previously ran.
This commit returns a result of the target so promises can still resolve but doesn't change
the flow of how the make file works.

arturadib/shelljs,freitagbr/shelljs,psema4/shelljs,jcoreio/shelljs,blockloop/shelljs,zhangda89/shelljs,beni55/shelljs,mcanthony/shelljs,rezonant/shelljs,quietshu/shelljs,shelljs/shelljs,sanemat/shelljs,a-x-/shelljs