deviseを使うときに躓いたのでメモ
Gemfileに以下を記述し、bundle installを実行

gem 'devise'

次に、rails generate devise:installすると以下のエラー

/home/vagrant/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/bundler-1.14.6/lib/bundler/runtime.rb:94:in `rescue in block (2 levels) in require': There was an error while trying to load the gem 'devise'.
Gem Load Error is: undefined method `alias_method_chain' for ActionDispatch::Routing::RouteSet:Class
Did you mean?  alias_method
Backtrace for gem load error is:

Gemfileの記述を以下に変更で解決

gem 'devise', git: 'https://github.com/plataformatec/devise.git', branch: 'master'

###参照

undefined method `alias_method_chain (Rails 5.1, ruby 2.4) #4511