Update Go versions in CI. (#758)

Drop support for Go < 1.20.

Author: sbarzowski

.github/workflows/ci.yml

@@ -25,16 +25,13 @@ jobs:
           # - goVersion: "1"
           #   GOARCH: "ppc64le"
           #   SKIP_PYTHON_BINDINGS_TESTS: "0"
-          - goVersion: "1.17"
-            GOARCH: "amd64"
-            SKIP_PYTHON_BINDINGS_TESTS: "0"
-          - goVersion: "1.18"
+          - goVersion: "1.20"
             GOARCH: "amd64"
             SKIP_PYTHON_BINDINGS_TESTS: "0"
-          - goVersion: "1.19"
+          - goVersion: "1.21"
             GOARCH: "amd64"
             SKIP_PYTHON_BINDINGS_TESTS: "0"
-          - goVersion: "1.20"
+          - goVersion: "1.22"
             GOARCH: "amd64"
             SKIP_PYTHON_BINDINGS_TESTS: "0"
     runs-on: ubuntu-latest

README.md

@@ -16,16 +16,12 @@ This code is known to work on Go 1.12 and above. We recommend always using the n
 ## Installation instructions
 
 ```shell
-# go >= 1.17
 # Using `go get` to install binaries is deprecated.
 # The version suffix is mandatory.
 go install github.com/google/go-jsonnet/cmd/jsonnet@latest
 
 # Or other tools in the 'cmd' directory
 go install github.com/google/go-jsonnet/cmd/jsonnet-lint@latest
-
-# go < 1.17
-go get github.com/google/go-jsonnet/cmd/jsonnet
 ```
 
 It's also available on Homebrew: