Add go-version file to control exact version of Go

It was found that the build steps were actually downloading an older
version of Go 1.17 and not the expected latest version. This changes
adds a go-version file for explicitly setting the version to be used for
test builds. The circle configuration has been updated to set the go
version as an environment variable before executing any install
commands.

.circleci/config.yml

@@ -15,27 +15,24 @@ executors:
     resource_class: medium+
   darwin:
     macos:
-      xcode: "13.4.0"
+      xcode: "13.4.1"
 
 commands:
   install-go-run-tests-unix:
     parameters:
       GOOS:
         type: string
-      GOVERSION:
-        type: string
     steps:
       - checkout
-      - run: curl https://dl.google.com/go/go<< parameters.GOVERSION >>.<< parameters.GOOS >>-amd64.tar.gz | tar -C ~/ -xz
+      - run: export GOVERSION=$(cat .go-version)
+      - run: curl https://dl.google.com/go/go${GOVERSION}.<< parameters.GOOS >>-amd64.tar.gz | tar -C ~/ -xz
       - run: GO111MODULE=on PATH="$PATH:$HOME/go/bin/" ~/go/bin/go test ./... -race -coverprofile=coverage.txt  -covermode=atomic
   install-go-run-tests-windows:
-    parameters:
-      GOVERSION:
-        type: string
     steps:
       - checkout
-      - run: curl https://dl.google.com/go/go<< parameters.GOVERSION >>.windows-amd64.zip --output ~/go<< parameters.GOVERSION >>.windows-amd64.zip
-      - run: unzip ~/go<< parameters.GOVERSION >>.windows-amd64.zip -d ~/
+      - run: export GOVERSION=$(cat .go-version)
+      - run: curl https://dl.google.com/go/go${GOVERSION}.windows-amd64.zip --output ~/go${GOVERSION}.windows-amd64.zip
+      - run: unzip ~/go${GOVERSION}.windows-amd64.zip -d ~/
       - run: GO111MODULE=on PATH="$PATH:$HOME/go/bin/" ~/go/bin/go test ./... -coverprofile=coverage.txt  -covermode=atomic
 
 # Golang CircleCI 2.0 configuration file
@@ -58,14 +55,12 @@ jobs:
     steps:
       - install-go-run-tests-unix:
           GOOS: darwin
-          GOVERSION: "1.17"
   test-windows:
     executor:
       name: win/vs2019
       shell: bash.exe
     steps:
-      - install-go-run-tests-windows:
-          GOVERSION: "1.17"
+      - install-go-run-tests-windows
   check-lint:
     executor: golang
     resource_class: xlarge

.go-version

@@ -0,0 +1 @@
+1.17.13