Make parseAPTConfigLine public

We already have a way to go from a repository to a line, via
`Repository.APTConfigLine`. There is a valid usecase to have the
reverse, go from a line to a Repository: for instance some software will
expect such a line as input/output (Ansible's apt_repository's repo for
instance). Given that it's unlikely that the implementation of it will
see breaking changes, I don't see any reason to keep it private.

Author: mickael-carl

repos.go

@@ -107,7 +107,7 @@ func (r *Repository) APTConfigLine() string {
 
 var aptConfigLineRegexp = regexp.MustCompile(`^(# )?(deb|deb-src)(?: \[(.*)\])? ([^ ]+) ([^ ]+) ([^#\n]+)(?: +# *(.*))?$`)
 
-func parseAPTConfigLine(line string) *Repository {
+func ParseAPTConfigLine(line string) *Repository {
 	match := aptConfigLineRegexp.FindAllStringSubmatch(line, -1)
 	if len(match) == 0 || len(match[0]) < 6 {
 		return nil