setup in repository-base-0.4.1

- old
+ new

@@ -26,10 +26,10 @@
 gem install bundler --no-doc -v 1.16.1
 gem install kramdown -v 1.16.2 # for YARD Markdown doc generation
 gem install yard -v 0.9.12
 yard config --gem-install-yri
 gem install json -v 2.1.0
-gem install activemodel -v 4.2.10
+gem install activemodel -v 4.2.3
 gem install rake -v 12.3.0
 gem install rspec -v 3.7.0
 gem install rubocop -v 0.52.1
 gem install simplecov -v 0.15.1
 gem install awesome_print -v 1.8.0