Update supported go versions to latest three (#149)

.github/workflows/go.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go: [ '1.18.1', '1.17.6', '1.16.5' ]
+        go: [ '1.22', '1.21', '1.20' ]
     steps:
     - uses: actions/checkout@v4
 

README.md

@@ -74,7 +74,7 @@ To update Objx to the latest version, run:
     go get -u github.com/stretchr/objx
 
 ### Supported go versions
-We currently support the most recent major Go versions from 1.13 onward.
+We currently support the three recent major Go versions.
 
 ## Contributing
 Please feel free to submit issues, fork the repository and send pull requests!

go.mod

@@ -1,7 +1,13 @@
 module github.com/stretchr/objx
 
-go 1.13
+go 1.20
 
 require github.com/stretchr/testify v1.8.2
 
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
+
 exclude github.com/stretchr/testify v1.8.0