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]>

Gemfile.lock

@@ -2,7 +2,7 @@ PATH
   remote: .
   specs:
     pubsub_tie (0.0.1)
-      google-cloud-pubsub (>= 1.6.0)
+      google-cloud-pubsub (~> 1.6)
 
 GEM
   remote: https://rubygems.org/
@@ -60,7 +60,7 @@ GEM
     multipart-post (2.1.1)
     os (1.1.0)
     public_suffix (4.0.5)
-    rake (10.5.0)
+    rake (13.0.1)
     rly (0.2.3)
     rspec (3.9.0)
       rspec-core (~> 3.9.0)
@@ -89,7 +89,7 @@ DEPENDENCIES
   byebug
   google-cloud-pubsub (>= 1.6.0)
   pubsub_tie!
-  rake (~> 10.0)
+  rake (~> 13.0)
   rspec (~> 3.0)
 
 BUNDLED WITH

pubsub_tie.gemspec

@@ -30,7 +30,7 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency 'google-cloud-pubsub', '~> 1.6'
 
-  spec.add_development_dependency "rake", '~> 10.0'
+  spec.add_development_dependency "rake", '~> 13.0'
   spec.add_development_dependency "bundler", '~> 1.16'
   spec.add_development_dependency "rspec", '~> 3.0'
 end