Setup/UpgradeData.php
private function upgrade108($oldConfigPaths, $newConfigPaths)
    {
        foreach ($oldConfigPaths as $key => $value) {
            $oldValue = $this->scopeConfig->getValue($value);
            if ($oldValue != null) {
                $this->configWriter->save($newConfigPaths[$key], $oldValue); // @codingStandardsIgnoreLine - currently best way to resolve this
            }
        }
    }
private function upgrade108($oldConfigPaths, $newConfigPaths)
    {
        foreach ($oldConfigPaths as $key => $value) {
            $oldValue = $this->scopeConfig->getValue($value);
            if ($oldValue != null) {
                $this->configWriter->save($newConfigPaths[$key], $oldValue); // @codingStandardsIgnoreLine - currently best way to resolve this
            }
        }
    }
Config path changes
@param $oldConfigPaths
@param $newConfigPaths