Test: impactx.__version__

Make sure this is not empty.

tests/python/test_impactx.py

@@ -12,9 +12,17 @@
 import pytest
 
 import amrex.space3d as amr
+import impactx
 from impactx import ImpactX, RefPart, distribution, elements
 
 
+def test_impactx_module():
+    """
+    Tests the basic modules we provide.
+    """
+    assert impactx.__version__  # version must not be empty
+
+
 def test_impactx_fodo_file():
     """
     This tests an equivalent to main.cpp in C++