github: test 1.18 and 1.19 (#34)

Author: changkun

.github/workflows/clipboard.yml

@@ -21,13 +21,13 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        go: [ '1.16.x', '1.17.x' ]
+        go: ['1.16.x', '1.17.x', '1.18.x', '1.19.x']
     steps:
     - name: Install and run dependencies (xvfb libx11-dev)
       if: ${{ runner.os == 'Linux' }}
       run: |
         sudo apt update
-        sudo apt install -y xvfb libx11-dev libegl1-mesa-dev libgles2-mesa-dev
+        sudo apt install -y xvfb libx11-dev x11-utils libegl1-mesa-dev libgles2-mesa-dev
         Xvfb :0 -screen 0 1024x768x24 > /dev/null 2>&1 &
         # Wait for Xvfb
         MAX_ATTEMPTS=120 # About 60 seconds