Add basic test for .glb file

tests/test_glb_codec.py

@@ -0,0 +1,23 @@
+import pytest
+import tests.test_helpers as helpers
+
+
+def test_glb_codec():
+    """
+    Basic test of the GLB codec plugin.
+    """
+    test_file = helpers.get_test_file_location("cube_assy.py")
+
+    command = [
+        "python",
+        "src/cq_cli/main.py",
+        "--codec",
+        "glb",
+        "--infile",
+        test_file,
+    ]
+    out, err, exitcode = helpers.cli_call(command)
+
+    assert out.decode().startswith("b'glTF")
+
+