Update default gems list at 2ffd6c2 [ci skip]

Author: matzbot

NEWS.md

@@ -142,6 +142,7 @@ The following default gems are updated.
 * bundler 2.7.0.dev
 * erb 5.0.1
 * io-console 0.8.1
+* io-nonblock 0.3.2
 * json 2.12.2
 * optparse 0.7.0.dev.2
 * prism 1.4.0