Moving fully to GH actions. (#1288)

Signed-off-by: bwplotka <bwplotka@gmail.com>

.github/workflows/Circle-ci.yml → .github/workflows/go.yml

@@ -1,15 +1,15 @@
-name: Test and Lint
-
+---
+name: Go
 on:
-  push:
-    branches:
-      - main
   pull_request:
+  push:
     branches:
       - main
+      - 'release-*'
 
 jobs:
   test:
+    name: Tests
     runs-on: ubuntu-latest
 
     strategy:

README.md

@@ -1,7 +1,7 @@
 # Prometheus Go client library
 
-[![CircleCI](https://circleci.com/gh/prometheus/client_golang/tree/main.svg?style=svg)](https://circleci.com/gh/prometheus/client_golang/tree/main)
-[![Go Report Card](https://goreportcard.com/badge/github.com/prometheus/client_golang)](https://goreportcard.com/report/github.com/prometheus/client_golang)
+[![CI](https://github.com/prometheus/client_golang/actions/workflows/ci.yml/badge.svg)](https://github.com/prometheus/client_golang/actions/workflows/ci.yml)
+[[![Go Report Card](https://goreportcard.com/badge/github.com/prometheus/client_golang)](https://goreportcard.com/report/github.com/prometheus/client_golang)
 [![Go Reference](https://pkg.go.dev/badge/github.com/prometheus/client_golang.svg)](https://pkg.go.dev/github.com/prometheus/client_golang)
 [![Slack](https://img.shields.io/badge/join%20slack-%23prometheus--client_golang-brightgreen.svg)](https://slack.cncf.io/)