Specify Go version for release workflow

Author: samcoe

.github/workflows/release.yml

@@ -17,6 +17,11 @@ jobs:
         uses: actions/checkout@v2
         with:
           fetch-depth: 0
+      -
+         name: Set up Go
+         uses: actions/setup-go@v2
+         with:
+           go-version: 1.16
       -
         name: Import GPG key
         id: import_gpg