Revert "remove dropna text"

jreback · jreback · commit bd5dcd3ffbba · 2018-06-28T20:41:53.000-04:00
This reverts commit 6d5c67b.
diff --git a/pandas/core/arrays/base.py b/pandas/core/arrays/base.py
@@ -49,6 +49,7 @@ class ExtensionArray(object):
     methods:
 
     * fillna
+    * dropna
     * unique
     * factorize / _values_for_factorize
     * argsort / _values_for_argsort
