Add Go 1.18 to our supported versions. (#2679)

* Adds go1.18 to tests, moves default version to 1.17

* Added note to readme.

* Update CHANGELOG.md

Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

* Update README.md

Co-authored-by: Robert Pająk <pellared@hotmail.com>

* Move default go version back to 1.16

* Move changelog entry to unreleased section

Co-authored-by: Chester Cheung <cheung.zhy.csu@gmail.com>
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>
Co-authored-by: Robert Pająk <pellared@hotmail.com>
Co-authored-by: Tyler Yahn <codingalias@gmail.com>

.github/workflows/ci.yml

@@ -109,7 +109,7 @@ jobs:
   compatibility-test:
     strategy:
       matrix:
-        go-version: [1.17, 1.16]
+        go-version: [1.18, 1.17, 1.16]
         os: [ubuntu-latest, macos-latest, windows-latest]
         # GitHub Actions does not support arm* architectures on default
         # runners. It is possible to acomplish this with a self-hosted runner

CHANGELOG.md

@@ -13,6 +13,10 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 This update is a breaking change of the unstable Metrics API.
 Code instrumented with the `go.opentelemetry.io/otel/metric` will need to be modified.
 
+### Added
+
+- Add go 1.18 to our compatibility tests. (#2679)
+
 ### Changed
 
 - The metrics API has been significantly changed. (#2587)

README.md

@@ -41,20 +41,28 @@ This project is tested on the following systems.
 
 | OS      | Go Version | Architecture |
 | ------- | ---------- | ------------ |
+| Ubuntu  | 1.18       | amd64        |
 | Ubuntu  | 1.17       | amd64        |
 | Ubuntu  | 1.16       | amd64        |
+| Ubuntu  | 1.18       | 386          |
 | Ubuntu  | 1.17       | 386          |
 | Ubuntu  | 1.16       | 386          |
+| MacOS   | 1.18       | amd64        |
 | MacOS   | 1.17       | amd64        |
 | MacOS   | 1.16       | amd64        |
+| Windows | 1.18       | amd64        |
 | Windows | 1.17       | amd64        |
 | Windows | 1.16       | amd64        |
+| Windows | 1.18       | 386          |
 | Windows | 1.17       | 386          |
 | Windows | 1.16       | 386          |
 
 While this project should work for other systems, no compatibility guarantees
 are made for those systems currently.
 
+Go 1.18 was added in March of 2022.
+Go 1.16 will be removed around June 2022.
+
 ## Getting Started
 
 You can find a getting started guide on [opentelemetry.io](https://opentelemetry.io/docs/go/getting-started/).