Add Ubuntu 20.04 GitHub actions build environment

Signed-off-by: Alexander Scheel <[email protected]>

Author: cipherboy

.github/workflows/main.yml

@@ -63,4 +63,3 @@ jobs:
         files: build-osx/scap-workbench-${{ steps.get_version.outputs.VERSION }}.dmg
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-

.github/workflows/ubuntu.yml

@@ -0,0 +1,23 @@
+name: OpenScap Workbench CI
+
+# Controls when the action will run. Triggers the workflow on push or pull request
+# events but only for the master branch
+on: [push, pull_request]
+
+jobs:
+  build-ubuntu:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Install required dependencies
+      run: |
+        sudo apt install -y build-essential openssh-client libopenscap-dev
+        sudo apt install -y libqt5xmlpatterns5-dev ssh-askpass asciidoc
+        sudo apt install -y libpolkit-agent-1-0
+    - name: Build SCAP Workbench
+      run: |
+        mkdir -p build
+        pushd build
+        cmake ..
+        make
+        popd