Integrate GitHub Actions.

- Automatically build with Go 1.12.
- Check for stale issues.

.gitlab/workflows/go.yml

@@ -0,0 +1,22 @@
+name: Go
+
+on: [push]
+
+jobs:
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+
+      - name: Set up Go 1.12
+        uses: actions/setup-go@v1
+        with:
+          go-version: 1.12
+        id: go
+
+      - name: Check out code into the Go module directory
+        uses: actions/checkout@v1
+
+      - name: Build
+        run: go build -v .

.gitlab/workflows/stale.yml

@@ -0,0 +1,19 @@
+name: Mark stale issues and pull requests
+
+on:
+  schedule:
+    - cron: "0 0 * * *"
+
+jobs:
+  stale:
+
+    runs-on: ubuntu-latest
+    
+    steps:
+      - uses: actions/stale@v1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          stale-issue-message: 'Stale issue message'
+          stale-pr-message: 'Stale pull request message'
+          stale-issue-label: 'no-issue-activity'
+          stale-pr-label: 'no-pr-activity'

README.md

@@ -1,6 +1,6 @@
 # ![Logo](img/logo_32.png) IceCon RCON client
 
-[![Release version](https://img.shields.io/github/release/icedream/icecon.svg?maxAge=2592000)](https://github.com/icedream/icecon/releases) [![Jenkins build status](https://img.shields.io/jenkins/s/https/ci.icedream.pw/icecon.svg?maxAge=2592000)](https://ci.icedream.pw/job/icecon/) ![Maintained?](https://img.shields.io/maintenance/yes/2018.svg?maxAge=2592000)
+[![Release version](https://img.shields.io/github/release/icedream/icecon.svg?maxAge=2592000)](https://github.com/icedream/icecon/releases) [![Jenkins build status](https://img.shields.io/jenkins/build/https/ci.icedream.tech/job/github/job/icedream/job/icecon/job/develop.svg?maxAge=2592000)](https://ci.icedream.tech/job/github/job/icedream/job/icecon) ![Maintained?](https://img.shields.io/maintenance/yes/2019.svg?maxAge=2592000)
 
 *IceCon* is a Q3-compatible RCON client. It can connect to any server that implements RCON over a Q3-compatible network protocol (UDP) and even comes with a nice, straight minimal GUI.