'Update an Organization Release\'s File
Update metadata of an existing file.  Currently only the name of
the file can be changed.
:pparam string organization_slug: the slug of the organization the
release belongs to.
:pparam string version: the version identifier of the release.
:pparam string file_id: the ID of the file to update.
:param string name: the new name of the file.
:param string dist: the name of the dist.
:auth: required'

def put(self, request, organization, version, file_id):

    try:
        release = Release.objects.get(organization_id=organization.id, version=version)
    except Release.DoesNotExist:
        raise ResourceDoesNotExist
    if (not self.has_release_permission(request, organization, release)):
        raise PermissionDenied
    try:
        releasefile = ReleaseFile.objects.get(release=release, id=file_id)
    except ReleaseFile.DoesNotExist:
        raise ResourceDoesNotExist
    serializer = ReleaseFileSerializer(data=request.DATA)
    if (not serializer.is_valid()):
        return Response(serializer.errors, status=400)
    result = serializer.object
    releasefile.update(name=result['name'])
    return Response(serialize(releasefile, request.user))
