[actions] add qt gui builder

.github/workflows/build-qt.yml

@@ -0,0 +1,20 @@
+name: Build on Ubuntu
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    name: With QT GUI
+    runs-on: ubuntu-16.04
+    steps:
+    - uses: actions/checkout@v2
+    - name: install packages
+      run: |
+        sudo add-apt-repository ppa:mhier/libboost-latest
+        sudo apt-get update
+        sudo apt-get install build-essential qt5-default libqt5gui5 libboost1.74-dev libminiupnpc-dev libssl-dev zlib1g-dev
+    - name: build application
+      run: |
+        cd qt/i2pd_qt
+        qmake
+        make USE_AVX=no USE_AESNI=no USE_UPNP=yes -j3