make an appimage from Xenial for LTS purposes

.github/workflows/nightly_win_lin.yml

@@ -77,6 +77,29 @@ jobs:
         asset_name: RetroArch-Linux-x86_64-Nightly.AppImage
         overwrite: true
 
+  Linux_LTS:
+    name: Build RetroArch LTS Linux AppImage Nightly
+    runs-on: ubuntu-16.04
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Fetch dependencies
+      run: sudo apt-get update ; sudo apt-get install libasound2-dev libavcodec-dev libavdevice-dev libavformat-dev libavutil-dev libc6-dev libdbus-1-dev libdrm-dev libegl1-mesa-dev libfreetype6-dev libgbm-dev libglm-dev libjack-jackd2-dev libopenal-dev libpulse-dev libsdl2-dev libswscale-dev libudev-dev libusb-1.0-0-dev libv4l-dev libvulkan-dev libxinerama-dev libxml2-dev libxv-dev libxxf86vm-dev pkg-config python3-dev qt5-default qtbase5-dev wayland-protocols x11proto-xext-dev zlib1g-dev
+    - name: Fetch linuxdeploy
+      run: wget https://github.com/linuxdeploy/linuxdeploy/releases/download/continuous/linuxdeploy-x86_64.AppImage && chmod +x linuxdeploy-x86_64.AppImage
+    - name: Fetch RetroArch source tree
+      run: git clone https://github.com/libretro/RetroArch.git
+    - name: Build RetroArch
+      run: cd RetroArch && mkdir AppDir && ./configure --prefix=/usr && make -j8 && make install DESTDIR=AppDir prefix=/usr && ../linuxdeploy-x86_64.AppImage --appdir AppDir --output appimage && mv RetroArch*.AppImage ../RetroArch-Linux-x86_64-Nightly.AppImage
+    - name: Upload RetroArch AppImage
+      uses: svenstaro/upload-release-action@v2
+      with:
+        repo_token: ${{ secrets.GITHUB_TOKEN }}
+        file: RetroArch-Linux-x86_64-Nightly.AppImage
+        tag: Linux_LTS_Nightlies
+        asset_name: RetroArch-Linux-x86_64-Nightly.AppImage
+        overwrite: true
+
   Windows:
     name: Build RetroArch Nightly Windows
     needs: Assets