Update default gems list at 73404e8f12 [ci skip]

NEWS.md

@@ -404,6 +404,7 @@ Note: We're only listing outstanding class updates.
     * ostruct 0.5.5
     * pathname 0.2.1
     * pp 0.4.0
+    * pstore 0.1.2
     * psych 5.0.0.dev
     * racc 1.6.1
     * rdoc 6.5.0