add github workflow to build the app in diff OSes.

.github/workflows/main.yml

@@ -0,0 +1,51 @@
+name: Build App
+
+on: push
+
+jobs:
+  build:
+
+    strategy:
+      matrix:
+        platform: [windows-latest, macos-latest, ubuntu-latest]
+
+    runs-on: ${{ matrix.platform }}
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Setup Python environment
+      uses: actions/setup-python@v1
+      with:
+        python-version: 3.7.6
+
+    - name: Install Pipenv
+      run: |
+        python -m pip install --upgrade pip
+        pip install pipenv
+  
+    - name: Install FBS requirements
+      run: |
+        sudo apt-get update
+        sudo apt-get install ruby ruby-dev rubygems build-essential
+
+        sudo gem install --no-document fpm
+
+        fpm --version
+
+      if: matrix.platform == 'ubuntu-latest'
+
+    - name: Install Package dependencies
+      run: |
+        pipenv install
+        pipenv graph
+    
+    - name: Build app
+      run: |
+        pipenv run fbs freeze
+
+    - name: Make installer
+      run: |
+        pipenv run fbs installer
+
+