Update rails (#251)

* Rails 8.0 support

* Update to Bot API 8.0

gemfiles/rails_80.gemfile

@@ -0,0 +1,21 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "actionpack", "~> 8.0.0"
+gem "railties", "~> 8.0.0"
+
+group :development do
+  gem "appraisal", "~> 2.2"
+  gem "debug", "~> 1.9.2"
+  gem "sdoc", "~> 2.0.3"
+  gem "telegram-bot-types", "~> 0.6.3"
+  gem "rspec", "~> 3.12.0"
+  gem "rspec-its", "~> 1.3.0"
+  gem "rspec-rails", "~> 4.0.2"
+  gem "rubocop", "~> 1.59.0"
+  gem "rubocop-rails", "~> 2.23.1"
+  gem "coveralls", "~> 0.8.23", require: false
+end
+
+gemspec path: "../"