Bump Expected Minimum Go Version to 1.17 (#175)

Reference: #174

Author: bflad

.changelog/175.txt

@@ -0,0 +1,3 @@
+```release-note:note
+This Go module has been updated to Go 1.17 per the [Go support policy](https://golang.org/doc/devel/release.html#policy). Any consumers building on earlier Go versions may experience errors.
+```

.github/workflows/ci-go.yml

@@ -33,7 +33,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: [ '1.17', '1.16' ]
+        go-version: [ '1.18', '1.17' ]
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-go@v2

.go-version

@@ -1 +1 @@
-1.16.13
+1.17.8

.golangci.yml

@@ -17,7 +17,7 @@ linters:
     # - paralleltest # Reference: https://github.com/kunwardeep/paralleltest/issues/14
     - predeclared
     - staticcheck
-    # - tenv # TODO: Enable when upgrading Go 1.16 to 1.17
+    - tenv
     - unconvert
     - unparam
     - varcheck

README.md

@@ -29,6 +29,12 @@ Providers built on terraform-plugin-go will only be usable with Terraform
 v0.12.0 and later. Developing providers for versions of Terraform below 0.12.0
 is unsupported by the Terraform Plugin SDK team.
 
+## Go Compatibility
+
+This project follows the [support policy](https://golang.org/doc/devel/release.html#policy) of Go as its support policy. The two latest major releases of Go are supported by the project.
+
+Currently, that means Go **1.17** or later must be used when including this project as a dependency.
+
 ## Getting Started
 
 terraform-plugin-go is targeted towards experienced Terraform developers.

go.mod

@@ -1,6 +1,6 @@
 module github.com/hashicorp/terraform-plugin-go
 
-go 1.16
+go 1.17
 
 require (
 	github.com/google/go-cmp v0.5.7
@@ -16,3 +16,19 @@ require (
 	google.golang.org/grpc/cmd/protoc-gen-go-grpc v1.2.0
 	google.golang.org/protobuf v1.28.0
 )
+
+require (
+	github.com/fatih/color v1.7.0 // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/hashicorp/terraform-svchost v0.0.0-20200729002733-f050f53b9734 // indirect
+	github.com/hashicorp/yamux v0.0.0-20180604194846-3520598351bb // indirect
+	github.com/mattn/go-colorable v0.1.4 // indirect
+	github.com/mattn/go-isatty v0.0.10 // indirect
+	github.com/oklog/run v1.0.0 // indirect
+	github.com/vmihailenco/tagparser v0.1.1 // indirect
+	golang.org/x/net v0.0.0-20210119194325-5f4716e94777 // indirect
+	golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 // indirect
+	golang.org/x/text v0.3.3 // indirect
+	google.golang.org/appengine v1.6.5 // indirect
+	google.golang.org/genproto v0.0.0-20200526211855-cb27e3aa2013 // indirect
+)