UPGRADE.md in quandl_data-1.2.0 vs UPGRADE.md in quandl_data-1.2.1

@@ -1,7 +1,12 @@
+## 1.2.1
+
+* add Data#to_date_str that returns data as "yyyy-mm-dd"
+
+
 ## 1.2.0
 
-* bump quandl_operation, data now defaults to return Dates instead of Julian Dates
+* bump quandl_operation, data returns Dates instead of Julian Dates
 
 
 ## 1.1.4
 
 * force incoming data to_a if it is kind_of Quandl::Data
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