chore(deps): update dependency rake to v13 [security]

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

git-contributors.gemspec

@@ -19,7 +19,7 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
 
   spec.add_development_dependency "bundler", "~> 1.5"
-  spec.add_development_dependency "rake", "~> 10"
+  spec.add_development_dependency "rake", "~> 13"
 
   spec.add_dependency 'diffy', '~> 3.0'
   spec.add_dependency 'inquirer', '~> 0'