bundle install で Killedされてインストールできない

vagrant環境でRailsチュートリアル6章をやっています。
password_digestカラムを追加するマイグレーションファイルを作成し
gemfileにgem 'bcrypt','3.1.11'　を追加。
rails db:nigrateコマンドを入力

$ bundle install
The dependency tzinfo-data (>= 0) will be unused by any of the platforms Bundler is installing for. Bundler is installing for ruby but the dependency is only for x86-mingw32, x86-mswin32, x64-mingw32, java. To add those platforms to the bundle, run `bundle lock --add-platform x86-mingw32 x86-mswin32 x64-mingw32 java`.
Fetching gem metadata from https://rubygems.org/.........Killed

と表示されたので

$ bundle lock --add-platform x86-mingw32 x86-mswin32 x64-mingw32 java
Fetching gem metadata from https://rubygems.org/.........Killed

ダメでした、Gemfileのplatforms: [:mingw, :mswin, :x64_mingw, :jruby]を消してbundle updateも同じくkilledされてしまいます。

解決方法がわかりません、ご回答よろしくお願いします。

gemfile
1source 'https://rubygems.org'
2
3gem 'rails',          '5.1.4'
4gem 'bcrypt',         '3.1.11'
5gem 'bootstrap-sass', '3.3.7'
6gem 'puma',           '3.9.1'
7gem 'sass-rails',     '5.0.6'
8gem 'uglifier',       '3.2.0'
9gem 'coffee-rails',   '4.2.2'
10gem 'jquery-rails',   '4.3.1'
11gem 'turbolinks',     '5.0.1'
12gem 'jbuilder',       '2.7.0'
13
14group :development, :test do
15  gem 'sqlite3', '1.3.13'
16  gem 'byebug',  '9.0.6', platform: :mri
17end
18
19group :development do
20  gem 'web-console',           '3.5.1'
21  gem 'listen',                '3.1.5'
22  gem 'spring',                '2.0.2'
23  gem 'spring-watcher-listen', '2.0.1'
24end
25
26group :test do
27  gem 'rails-controller-testing', '1.0.2'
28  gem 'minitest-reporters',       '1.1.14'
29  gem 'guard',                    '2.13.0'
30  gem 'guard-minitest',           '2.4.4'
31end
32
33group :production do
34  gem 'pg', '0.20.0'
35end
36
37# Windows環境ではtzinfo-dataというgemを含める必要があります
38gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
39

追記

ファイル等に変更は加えていないのですがエラー表示が変わりました

$ bundle install
The dependency tzinfo-data (>= 0) will be unused by any of the platforms Bundler is installing for. Bundler is installing for ruby but the dependency is only for x86-mingw32, x86-mswin32, x64-mingw32, java. To add those platforms to the bundle, run `bundle lock --add-platform x86-mingw32 x86-mswin32 x64-mingw32 java`.
Failed to load /home/vagrant/.gemrc because it doesn't contain valid YAML hash
Fetching gem metadata from https://rubygems.org/.........
Fetching gem metadata from https://rubygems.org/.
Resolving dependencies...
Using rake 12.3.1
Using concurrent-ruby 1.0.5
Using i18n 0.9.5
Using minitest 5.11.3
Using thread_safe 0.3.6
Fetching tzinfo 1.2.5
Installing tzinfo 1.2.5
Killed

$ bundle lock --add-platform x86-mingw32 x86-mswin32 x64-mingw32 java
Failed to load /home/vagrant/.gemrc because it doesn't contain valid YAML hash
Fetching gem metadata from https://rubygems.org/.........Killed