Use tag version of minitest-5.22.3

Author: hsbt

gems/bundled_gems

@@ -5,7 +5,7 @@
 # - repository-url: URL from where clone for test
 # - revision: revision in repository-url to test
 #   if `revision` is not given, "v"+`version` or `version` will be used.
-minitest        5.22.3  https://github.com/minitest/minitest d0a993f3be2ee2ebc0588155003c16918e971dc9
+minitest        5.22.3  https://github.com/minitest/minitest
 power_assert    2.0.3   https://github.com/ruby/power_assert
 rake            13.1.0  https://github.com/ruby/rake
 test-unit       3.6.2   https://github.com/test-unit/test-unit