Use newer octokit

Author: h0lyalg0rithm

jekyll-gist.gemspec

@@ -18,7 +18,7 @@ Gem::Specification.new do |spec|
   spec.required_ruby_version = ">= 2.3.0"
 
   spec.add_runtime_dependency "jekyll", ">= 3.7", "< 5.0"
-  spec.add_runtime_dependency "octokit", "~> 4.2"
+  spec.add_runtime_dependency "octokit", "~> 8.0"
 
   spec.add_development_dependency "bundler"
   spec.add_development_dependency "rake"