Generate default values of None for optional arguments

[ghostdogpr]

Example of function generated with the Github API:

def repositories[A](
        affiliations: Option[List[Option[RepositoryAffiliation]]],
        after: Option[String],
        before: Option[String],
        first: Option[Int],
        isFork: Option[Boolean],
        isLocked: Option[Boolean],
        last: Option[Int],
        orderBy: Option[RepositoryOrder],
        ownerAffiliations: Option[List[Option[RepositoryAffiliation]]],
        privacy: Option[RepositoryPrivacy]
    )(
        innerSelection: SelectionBuilder[RepositoryConnection, A]
    ): SelectionBuilder[Organization, A] = ???

It is inconvenient to have to pass None for each of them. We could add = None when generating the code.

[kitlangton]

I'm going to take a shot at this tomorrow morning :)