feat(create_prs): sleep at the end

[leszekbulawa]

Reasoning

Currently, when creating PRs with sleep, the procedure starts with the sleep.
This is not optimal, eg. it's possible that after waiting for a certain amount of time the user will be presented with an error.

➜  turbolift create-prs --sleep 30s
  OK   Reading campaign data (repos.txt, README.md)
  OK   Sleeping for 30s
 FAIL  Pushing changes in leszekbulawa/myrepo to origin: exit status 128

Description of change

Moved sleep to the end of create_prs function.

Before (starts with the sleep):

turbolift create-prs --sleep 30s 
  OK   Reading campaign data (repos.txt, README.md)
  OK   Sleeping for 30s
 WARN  Pushing changes in me/non-existing-repo to origin: Directory work/me/non-existing-repo does not exist - has it been cloned?

  OK   turbolift create-prs completed (0 OK, 1 skipped)

After:

 ~/dev/turbolift/turbolift create-prs --sleep 30s
  OK   Reading campaign data (repos.txt, README.md)
 WARN  Pushing changes in me/non-existing-repo to origin: Directory work/me/non-existing-repo does not exist - has it been cloned?

  OK   turbolift create-prs completed (0 OK, 1 skipped)