Merge pull request #3 from buildkite/dependabot/bundler/rake-13.0.6

Bump rake from 10.5.0 to 13.0.6

Author: jj-bk

Gemfile.lock

@@ -5,7 +5,7 @@ GEM
     knapsack (1.6.0)
       rake
       timecop (>= 0.1.0)
-    rake (10.5.0)
+    rake (13.0.6)
     rspec (3.4.0)
       rspec-core (~> 3.4.0)
       rspec-expectations (~> 3.4.0)