Merge pull request #90 from ruby-syntax-tree/dependabot/bundler/minitest-5.20.0

Bump minitest from 5.19.0 to 5.20.0

Author: github-actions[bot]

Gemfile.lock

@@ -14,7 +14,7 @@ GEM
       temple (>= 0.8.2)
       thor
       tilt
-    minitest (5.19.0)
+    minitest (5.20.0)
     prettier_print (1.2.1)
     rake (13.0.6)
     simplecov (0.22.0)