v1.3.0-wip-beta2

Provides:

• Signed Commits config
• Required review counter config
• Updated go-github lib
• Terraform 0.12.0-beta2 support (HCL 2 upgrade)

terraform-provider-github_v1.3.0-wip-beta2.zip contains windows_amd64, linux_amd64, darwin_amd64 folders, ready to be extracted on ~/.terraform.d/plugins