feature: Fixed failing doctest

Author: mhash1m

dffml/feature/feature.py

@@ -116,22 +116,23 @@ class and implement the fetch, parse, and calc methods. These methods are
 
     Examples
     --------
-
     Define a feature using load_def:
+
     >>> feature = Feature.load_def("example", "float", 10)
     >>> feature.dtype()
-    float
+    <class 'float'>
     >>> feature.NAME
-    "example"
+    'example'
     >>> feature.length()
     10
 
     Defining a feature directly using DefFeature:
-    >>> feature = DefFeature("example2", "int", 20)
+
+    >>> feature = DefFeature("example2", int, 20)
     >>> feature.dtype()
-    int
+    <class 'int'>
     >>> feature.NAME
-    "example2"
+    'example2'
     >>> feature.length()
     20
     """
@@ -174,7 +175,7 @@ def dtype(self) -> Type:
 
         >>> feature = Feature()
         >>> feature.dtype()
-        int
+        <class 'int'>
         """
         self.LOGGER.warning("%s dtype unimplemented", self)
         return int