feat(deploy-webapp): skip downloading if WEBAPP directory already exists

* fix some typo
style(indent): format properly
feat(remove-host): remove entry from ~/.ssh/known_hosts

fixes #44
fixes #3
refactor(uninstall): purge config directory in 'purge' task
fix(add-host): don't overwrite already existing host

fixes #61
feat(mk,add-host): translit name and remove space to get safe name

* add ivonc to dependencies