CI: run unit tests on Github Actions

Author: tstenner

.github/workflows/cppcmake.yml

@@ -38,3 +38,7 @@ jobs:
       with:
         name: pkg-${{ matrix.os }}
         path: build/install
+    - name: unit tests (internal functions)
+      run: build/install/bin/lsl_test_internal --order rand --durations yes
+    - name: unit tests (exported functions)
+      run: build/install/bin/lsl_test_exported --order rand --durations yes