Fix typo, add more tests

Author: ColeDCrawford

README.md

@@ -378,7 +378,8 @@ True
 False
 
 >>> parse_edtf("2004?-~06-~04")
-PartialUncertainOrApproximate: '2004?-~06-~04'>>> L2_PartialUncertainOrApproximate.is_approximate
+PartialUncertainOrApproximate: '2004?-~06-~04'
+>>> parse_edtf("2004?-~06-~04").is_approximate
 True
 >>> parse_edtf("2004?-~06-~04").is_uncertain
 True

edtf/parser/parser_classes.py

@@ -866,7 +866,7 @@ def __init__(
             all_ua,
         ]
         self.is_uncertain = any(
-            item.is_uncertain for item in uas if hasattr(item, "is_approximate")
+            item.is_uncertain for item in uas if hasattr(item, "is_uncertain")
         )
         self.is_approximate = any(
             item.is_approximate for item in uas if hasattr(item, "is_approximate")

edtf/parser/tests.py

@@ -253,6 +253,7 @@
     ("1984~/2004-06", (False, True, False)),
     ("2004-%06", (False, False, True)),
     ("2004?-~06-~04", (True, True, False)),
+    ("2004?-06-04", (True, False, False)),
     ("2011-~06-~04", (False, True, False)),
     ("2004-06-~01/2004-06-~20", (False, True, False)),
     ("156X~", (False, True, False)),