[Heroku][Git]うまくデプロイできない(Gemfile.lockのcommitがうまくいかない？)

###前提・実現したいこと
今、Railsでアプリケーションを作成してHerokuにデプロイしようとしています。
ところが、Herokuにgit pushでデプロイすると以下のようなエラーメッセージがでてきて動いてくれません。お願いします。

###発生している問題・エラーメッセージ

Bundler Output: Warning: the running version of Bundler is older than the version that created the lockfile. We suggest you upgrade to the latest version of Bundler by running `gem install bundler`.

You are trying to install in deployment mode after changing your Gemfile. Run `bundle install` elsewhere and add the updated Gemfile.lock to version control.     
       You have added to the Gemfile:
       * sqlite3 (= 1.3.9)
       * byebug (= 3.4.0)
       * web-console (= 2.0.0.beta3)
       * spring (= 1.1.3)
       * pg (= 0.17.1)
       * rails_12factor (= 0.0.2)

       You have deleted from the Gemfile:
       * byebug
       * spring
       * sqlite3
       * web-console (~> 2.0)
 !
 !     Failed to install gems via Bundler.

       Push rejected, failed to compile Ruby app

###試したこと
言われた通り、bundle installしてcommitしたりしてみましたが、Gemfile.lock等がcommitできないみたいです。

$ bundle install
$ git commit
>On branch master
>Changes not staged for commit:
        modified:   Gemfile.lock

>Untracked files:
        app/assets/javascripts/jquery.mobile-1.4.5.min.js
        app/assets/stylesheets/jquery.mobile-1.4.5.min.css
        app/views/wikitwitters/new.html.erb

>no changes added to commit
$ git add Gemfile.lock,app/assets/javascripts/jquery.mobile-1.4.5.min.js...
$ git commit
>On branch master
>Changes not staged for commit:
        modified:   Gemfile.lock

>Untracked files:
        app/assets/javascripts/jquery.mobile-1.4.5.min.js
        app/assets/stylesheets/jquery.mobile-1.4.5.min.css
        app/views/wikitwitters/new.html.erb

>no changes added to commit
$ git status
> On branch master
> Changes to be committed:
  (use "git reset HEAD <file>..." to unstage)

        modified:   Gemfile.lock
        new file:   app/assets/javascripts/jquery.mobile-1.4.5.min.js
        new file:   app/assets/stylesheets/jquery.mobile-1.4.5.min.css
        new file:   app/views/wikitwitters/new.html.erb

###追加情報
Gemfileの中身は以下です

source 'https://rubygems.org'

gem 'wikipedia-client'
gem 'twitter'

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.2.2'
# Use sqlite3 as the database for Active Record
# Use SCSS for stylesheets
gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.1.0'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby

# Use jquery as the JavaScript library
gem 'jquery-rails'
# Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
gem 'turbolinks'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.0'
# bundle exec rake doc:rails generates the API under doc/api.
gem 'sdoc', '~> 0.4.0', group: :doc

# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'

# Use Unicorn as the app server
# gem 'unicorn'

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

group :development, :test do
  gem 'sqlite3',     '1.3.9'
  gem 'byebug',      '3.4.0'
  gem 'web-console', '2.0.0.beta3'
  gem 'spring',      '1.1.3'
end

group :production do
  gem 'pg',             '0.17.1'
  gem 'rails_12factor', '0.0.2'
end