Evolve release process to conform to Terraform registry standards

[mdb]

In order to conform to the standards recommended by registry.terraform.io, evidently each provider release must meet the following criteria:

There are 1 or more zip files containing the built provider binary for a single architecture.

The binary name is terraform-provider-{NAME}-{VERSION}.

Formatted as terraform-provider-{NAME}-{VERSION}-{OS}-{ARCH}.zip

It's recommended to build for all of these os/architecture pairs if possible:

• darwin/amd64
• freebsd/386
• freebsd/amd64
• freebsd/arm
• linux/386
• linux/amd64
• linux/arm
• linux/arm64
• openbsd/386
• openbsd/amd64
• solaris/amd64
• windows/386
• windows/amd64

There is a terraform-provider-{NAME}-{VERSION}-SHASUMS file, which contains a sha256 sum for each zip file in the release.

shasum -a 256 *.zip > terraform-provider-{NAME}-{VERSION}-SHASUMS

There is a terraform-provider-{NAME}-{VERSION}-SHASUMS.sig file, which is a valid GPG signature of the terraform-provider-{NAME}-{VERSION}-SHASUMS file using the keypair.

gpg --detach-sign terraform-provider-{NAME}-{VERSION}-SHASUMS

Release is finalized (not a private draft).