updates capistrano to match the Gemfile

config/deploy.rb

@@ -1,5 +1,5 @@
 # config valid only for current version of Capistrano
-lock '3.5.0'
+lock '3.8.0'
 
 def deploysecret(key)
   @deploy_secrets_yml ||= YAML.load_file('config/deploy-secrets.yml')[fetch(:stage).to_s]
@@ -55,4 +55,4 @@ task :install_bundler_gem do
   on roles(:app) do
     execute "rvm use #{fetch(:rvm1_ruby_version)}; gem install bundler"
   end
-end
+end