[RHEL/7][Fedora] Update IPv6 Kernel Module to sysctl setting

- Migrate IPv6 kernel module disable to sysctl settings
- Enabled for Fedora
- Fixes #60
[RHEL/7] add Sysctl IPv6 Kernel check
Merge pull request #300 from redhatrises/kernel_ipv6_sysctl

[RHEL/7][Fedora] Update IPv6 Kernel Module to sysctl setting