add test to check that doit runs successfully

test/conftest.py

@@ -0,0 +1,8 @@
+import sys
+from pathlib import Path
+
+PROJDIR = str(Path(__file__).parent.parent)
+if PROJDIR not in sys.path:
+    print(PROJDIR)
+    sys.path.append(PROJDIR)
+

test/test_doit.py

@@ -0,0 +1,9 @@
+import dodo
+import doit
+from unittest.mock import patch
+
+
+def test_doit():
+    with patch('sys.exit') as exit:
+        doit.run(dodo)
+        exit.assert_called_with(0)