ruby2.4でrailsでmysqlを使いたい。

railsでmysqlを使おうとしたらエラーが出ました。

発生している問題・エラーメッセージ

>rails db:create

LoadError: cannot load such file -- mysql2/2.4/mysql2
.../config/application.rb:7:in `<top (required)>'
.../Rakefile:4:in `require_relative'
.../Rakefile:4:in `<top (required)>'
bin/rails:4:in `require'
bin/rails:4:in `<main>'

コマンド

>gem install mysql2

======================================================================================================

  You've installed the binary version of mysql2.
  It was built using MySQL Connector/C version 6.1.11.
  It's recommended to use the exact same version to avoid potential issues.

  At the time of building this gem, the necessary DLL files were retrieved from:
  http://cdn.mysql.com/Downloads/Connector-C/mysql-connector-c-6.1.11-win32.zip

  This gem *includes* vendor/libmysql.dll with redistribution notice in vendor/README.

======================================================================================================

Successfully installed mysql2-0.4.10-x64-mingw32
Parsing documentation for mysql2-0.4.10-x64-mingw32
Installing ri documentation for mysql2-0.4.10-x64-mingw32
Done installing documentation for mysql2 after 0 seconds
1 gem installed

ソース

database.yml

# SQLite version 3.x
#   gem install sqlite3
#
#   Ensure the SQLite 3 gem is defined in your Gemfile
#   gem 'sqlite3'
#
default: &default
  adapter: sqlite3
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  timeout: 5000

development:
  adapter: mysql2
  encoding: utf8
  database: rails_tutorial
  pool: 5
  username: root
  password:
  host: localhost

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  <<: *default
  database: db/test.sqlite3

production:
  <<: *default
  database: db/production.sqlite3

Gemfile

source 'https://rubygems.org'

git_source(:github) do |repo_name|
  repo_name = "#{repo_name}/#{repo_name}" unless repo_name.include?("/")
  "https://github.com/#{repo_name}.git"
end


# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '~> 5.1.4'
# Use mysql2 as the database for Active Record
gem 'mysql2'
# Use Puma as the app server
gem 'puma', '~> 3.7'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby

# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.2'
# Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
gem 'turbolinks', '~> 5'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.5'
# Use Redis adapter to run Action Cable in production
# gem 'redis', '~> 3.0'
# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'

# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development

group :development, :test do
  # Call 'byebug' anywhere in the code to stop execution and get a debugger console
  gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
  # Adds support for Capybara system testing and selenium driver
  gem 'capybara', '~> 2.13'
  gem 'selenium-webdriver'
end

group :development do
  # Access an IRB console on exception pages or by using <%= console %> anywhere in the code.
  gem 'web-console', '>= 3.3.0'
end

# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]

試したこと

rubyを2.3にダウングレード

補足情報(言語/FW/ツール等のバージョンなど)

Microsoft Windows [Version 10.0.16299.98]
ruby 2.4.2p198 (2017-09-14 revision 59899) [x64-mingw32]
Rails 5.1.4