Removing unused variable from convert.go
Removing unused variable from convert.go

Fixes #513
removed `ConvertSource` and `ConvertBuildConfig`, since they are no longer used.

containscafeine/kompose,ashetty1/kompose,surajnarwade/kompose,procrypt/kompose,procrypt/kompose,rupalibehera/kompose,kubernetes/kompose,gitlawr/kompose,gitlawr/kompose,gitlawr/kompose,cdrage/kompose,skippbox/kompose,rupalibehera/kompose,cdrage/kompose,kubernetes/kompose,containscafeine/kompose,surajnarwade/kompose,procrypt/kompose,ashetty1/kompose,ashetty1/kompose,skippbox/kompose,surajnarwade/kompose,skippbox/kompose,kadel/kompose,rupalibehera/kompose,containscafeine/kompose,kadel/kompose