Update rake requirement from ~> 10.0 to ~> 13.0

Updates the requirements on [rake](https://github.com/ruby/rake) to permit the latest version.
- [Release notes](https://github.com/ruby/rake/releases)
- [Changelog](https://github.com/ruby/rake/blob/master/History.rdoc)
- [Commits](ruby/rake@v10.5.0...v13.0.1)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Gemfile.lock

@@ -55,7 +55,7 @@ GEM
     psych (3.1.0)
     public_suffix (4.0.3)
     rainbow (3.0.0)
-    rake (10.5.0)
+    rake (13.0.1)
     reek (5.4.1)
       codeclimate-engine-rb (~> 0.4.0)
       kwalify (~> 0.7.0)
@@ -113,7 +113,7 @@ DEPENDENCIES
   codecov (~> 0.1.16)
   minitest (~> 5.8.4)
   minitest-around (~> 0.5.0)
-  rake (~> 10.0)
+  rake (~> 13.0)
   reek (~> 5.4.0)
   rubocop (< 1.0)
   simplecov (~> 0.18.1)

skunk.gemspec

@@ -44,7 +44,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "codecov", "~> 0.1.16"
   spec.add_development_dependency "minitest", "~> 5.8.4"
   spec.add_development_dependency "minitest-around", "~> 0.5.0"
-  spec.add_development_dependency "rake", "~> 10.0"
+  spec.add_development_dependency "rake", "~> 13.0"
   spec.add_development_dependency "reek", "~> 5.4.0"
   spec.add_development_dependency "rubocop", "< 1.0"
   spec.add_development_dependency "simplecov", "~> 0.18.1"