* New Providers added and updated vendoring for go-discover
* Vendor.json formatted using make vendorfmt
* Docs/Agent/auto-join: Added documentation for the new providers introduced in this PR
* Updated the golang.org/x/sys/unix in the vendor directory
* Agent: TestGoDiscoverRegistration updated to reflect the addition of new providers
* Deleted terraform.tfstate from vendor.
* Deleted terraform.tfstate.backup
Deleted terraform state file artifacts from unknown runs.
* Updated x/sys/windows vendor for Windows binary compilation
Update github.com/hashicorp/go-discover/provider/aws to support the
'addr_type' option which allows detection of private_v4, public_v4 and
public_v6 addresses.
Fixes#3471