Add Windows & Mac CI testing

.github/workflows/main.yml

@@ -6,7 +6,7 @@ on:
 
 jobs: 
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps: 
       - uses: actions/checkout@v2
 
@@ -69,3 +69,57 @@ jobs:
       - name: Run tests (Python 2)
         run: |
           cd tests && PYTHONWARNINGS=ignore python2 ./main.py && cd ..
+
+  test-windows:
+    runs-on: windows-2022
+    steps: 
+      - uses: actions/checkout@v2
+      
+      - name: Install dependencies
+        run: |
+          # Require cryptography >= 3.1 because in 3.0 and below, the backend param in load_key_and_certificates was still required.
+          pip3 install freezegun lxml pycryptodome rsa oscrypto "cryptography>=3.1"
+        shell: bash
+
+      - name: Run tests (Python 3)
+        run: |
+          cd tests && python3 ./main.py && cd ..
+        shell: bash
+      
+      - name: Setup Python 2
+        uses: actions/setup-python@v3
+        with: 
+          python-version: '2.x'
+      
+      - name: Install deps for Python 2
+        run: |
+          # Install Python2 stuff
+          python -m pip install freezegun mock lxml pycryptodome "rsa<=4.3" oscrypto cryptography==3.1 
+
+      - name: Run tests (Python 2)
+        run: |
+          cd tests && PYTHONWARNINGS=ignore python ./main.py && cd ..
+        shell: bash
+
+
+  test-mac:
+    runs-on: macos-11
+    steps: 
+      - uses: actions/checkout@v2
+      
+      - name: Install dependencies
+        run: |
+          # Require cryptography >= 3.1 because in 3.0 and below, the backend param in load_key_and_certificates was still required.
+          pip3 install freezegun lxml pycryptodome rsa oscrypto "cryptography>=3.1"
+          # Install Python2 stuff
+          curl https://bootstrap.pypa.io/pip/2.7/get-pip.py --output get-pip.py
+          python2 get-pip.py
+          pip2 install freezegun mock lxml pycryptodome "rsa<=4.3" oscrypto cryptography==3.1
+
+      - name: Run tests (Python 3)
+        run: |
+          cd tests && python3 ./main.py && cd ..
+
+      - name: Run tests (Python 2)
+        run: |
+          cd tests && PYTHONWARNINGS=ignore python2 ./main.py && cd ..