STEP 23: Handle promises and futures correctly for background process
STEP 23: Handle promises and futures correctly for background process

Summary:
The migration guide was missing information leading to errors in
upgrading to play. While this change works correctly it needs to
be verified by someone who understands scala better:

discordianfish/collins,discordianfish/collins,funzoneq/collins,byxorna/collins,box/collins,funzoneq/collins,defect/collins,tumblr/collins,box/collins,funzoneq/collins,byxorna/collins,funzoneq/collins,tumblr/collins,box/collins,discordianfish/collins,discordianfish/collins,discordianfish/collins,tumblr/collins,defect/collins,defect/collins,funzoneq/collins,byxorna/collins,box/collins,byxorna/collins,tumblr/collins,tumblr/collins,discordianfish/collins,defect/collins,defect/collins,defect/collins,tumblr/collins,byxorna/collins,byxorna/collins,funzoneq/collins