sync:purge cannot delete .unison.*.tmp directories #174
Description
It seems that the sync:purge command assumes when deleting .unison.*.tmp that these are plain files. But these can also be directories, which cause errors like:
⚠ Could not remove .unison directories: remove /Users/mpotter/Projects/test_project/.unison.backup.395ca72483ab4f09678f80ab2f9e01b9.unison.tmp: directory not empty
line 261 of project_sync.go references util.RemoveFile. Think it needs to also check for directories.