- added download test file

- not working
- need to fix download.py first

tests/test_download.py

@@ -0,0 +1,20 @@
+"""
+Tests for the download module of GLDAS.
+"""
+import os
+from datetime import datetime
+from merra.download import get_last_formatted_dir_in_dir
+from merra.download import get_first_formatted_dir_in_dir
+from merra.download import get_last_folder
+from merra.download import get_first_folder
+from merra.download import folder_get_version_first_last
+
+def test_get_last_dir_in_dir():
+    path = os.path.join(os.path.dirname(__file__),
+                        'folder_test', 'success')
+    last_dir = get_last_formatted_dir_in_dir(path, "{time:%Y}")
+    assert last_dir == '2018'
+
+
+if __name__ == '__main__':
+    test_get_last_dir_in_dir()