Add test_version.py

Author: Alison Wu

tests/test_version.py

@@ -0,0 +1,10 @@
+"""Unit tests for __version__.py
+"""
+
+import diffpy.utils
+
+
+def test_package_version():
+    """Ensure the package version is defined and not set to the initial placeholder."""
+    assert hasattr(diffpy.utils, "__version__")
+    assert diffpy.utils.__version__ != "0.0.0"