Changing Gemfile

As we've added new Gems to this project, we need to change part of the overall project configuration. This is contained in Gemfile, a simple list of Gems used in the project. The old version is as follows:

source :rubygems

gem "sinatra"
gem "thin"

The first line indicates a standard server for downloading Gems. This server has been deprecated for security reasons, so we'll change it in a moment.

Notice that Gemfile contains a line for the Sinatra Gem, which we referenced in the application, and an additional Gem, thin. This is a simple web server used by the Sinatra framework.

The modified Gemfile incorporates new Gems and a safer source:

source 'http://rubygems.org'

gem "sinatra"
gem "thin"
gem "json"
gem "mysql2"

When you modify Gemfile, you must incorporate changes using the following command:

bundle install

If you do not have "bundle" installed, you will have to install that gem before running bundle install. To do this, simply run the following command:

sudo gem install...