Try to use submodules

Signed-off-by: Adrien Gallouët <adrien@gallouet.fr>

.github/workflows/build.yml

@@ -0,0 +1,20 @@
+name: Build
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macOS-latest]
+
+    steps:
+    - uses: actions/checkout@v1
+      with:
+          submodules: true
+    - name: Build glorytun
+      run: |
+          ./sodium.sh
+          make