Merge pull request #18 from ruby-syntax-tree/dependabot/bundler/rake-13.1.0

Bump rake from 13.0.6 to 13.1.0

Author: github-actions[bot]

Gemfile.lock

@@ -8,7 +8,7 @@ GEM
   specs:
     docile (1.4.0)
     power_assert (2.0.3)
-    rake (13.0.6)
+    rake (13.1.0)
     simplecov (0.22.0)
       docile (~> 1.1)
       simplecov-html (~> 0.11)