FEATURES:
ProtocolVersion to ReattachConfig struct, enabling provider protocol v6 support in reattach mode, provided that Terraform and the provider plugin are both using go-plugin v1.4.1 or later. This change is backwards-compatible, as zero values for this field are interpreted as protocol v5. (#182)tfexec.Get() for downloading modules (#176)tfexec.Upgrade013() (#178)INTERNAL: