Set bundler version in Dockerfile

Author: ferrarimarco

Dockerfile

@@ -9,7 +9,7 @@ RUN apk add --no-cache \
 
 WORKDIR /
 COPY Gemfile Gemfile
-RUN gem install bundler --version "$(grep bundler Gemfile | awk -F "'" '{print $4}')" \
+RUN gem install bundler --version 2.2.15 \
   && bundle install --system \
   && gem uninstall bundler \
   && rm Gemfile

Gemfile

@@ -1,4 +1,3 @@
 source 'https://rubygems.org' do
-  gem 'bundler', '2.0.2'
   gem 'github_changelog_generator', '1.15.2'
 end