rails５でRspec実行時にエラーが出る

前提・実現したいこと

rails５でRspecを動かしたいのですが、
エラーが出ます。

Gemfile
1group :development, :test do
2 51   # Call 'byebug' anywhere in the code to stop execution and get a debugger     console
3 52   gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
4 53   gem 'rspec-rails'
5 54   gem 'factory_bot_rails'
6 55   gem 'guard'
7 56   gem 'guard-rspec'
8 57   gem 'terminal-notifier-guard'
9 58   gem 'rubocop'
10 59   gem 'rubocop-rspec'
11 60   gem 'rails-controller-testing'
12 61 end
13
14group :test do
15 73   # Adds support for Capybara system testing and selenium driver
16 74   gem 'capybara', '>= 2.15', '< 4.0'
17 75   gem 'selenium-webdriver'
18 76   # Easy installation and use of chromedriver to run system tests with Chrom    e
19 77   gem 'chromedriver-helper'
20 78 end

発生している問題・エラーメッセージ

bundle exec rspec ./ 実行時

An error occurred while loading ./sessions_controller_spec.rb.
Failure/Error: require 'rails_helper'
LoadError:
  cannot load such file -- rails_helper
./sessions_controller_spec.rb:1:in `require'
 ./sessions_controller_spec.rb:1:in `<top (required)>'

該当のソースコード

Ruby
11 require 'rails_helper'
2  2 
3  3  RSpec.describe 'SessionsController', type: :controller do
4  4 
5  5 before :each do
6  6    @user = build(:user)
7  7    end
8  8 
9  9 after :each do
10 10     @user = nil
11 11    end
12 12 
13 13  it 'user name validation' do
14 14  expect(@user).to be_valid
15 15  end
16 16 
17 17  end
18

試したこと

rails g rspec:install

実行時すでにファイルがあるのでコンフリクトが発生する。

Running via Spring preloader in process 2829
    conflict  .rspec
Overwrite /Users/user/Desktop/wanokokoro/.rspec? (enter "h" for help) [Ynaqdh] n
        skip  .rspec
       exist  spec
    conflict  spec/spec_helper.rb
Overwrite /Users/user/Desktop/wanokokoro/spec/spec_helper.rb? (enter "h" for help) [Ynaqdh] n
        skip  spec/spec_helper.rb
    conflict  spec/rails_helper.rb
Overwrite /Users/user/Desktop/wanokokoro/spec/rails_helper.rb? (enter "h" for help) [Ynaqdh] n
        skip  spec/rails_helper.rb