Specify Ruby version

nokogiri-1.11.3-x86_64-darwin requires ruby version < 3.1.dev, >= 2.5,
which is incompatible with the current version, ruby 2.4.3p205

.ruby-version

@@ -0,0 +1 @@
+2.5.7

Gemfile

@@ -5,6 +5,7 @@ git_source(:github) do |repo_name|
   "https://github.com/#{repo_name}.git"
 end
 
+ruby '2.5.7'
 
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '~> 5.1.7'

Gemfile.lock

@@ -152,5 +152,8 @@ DEPENDENCIES
   spring-watcher-listen (~> 2.0.0)
   tzinfo-data
 
+RUBY VERSION
+   ruby 2.5.7p206
+
 BUNDLED WITH
-   2.2.3
+   2.2.4

README.md

@@ -67,6 +67,7 @@ We encourage the use of any libraries for everything except the search functiona
 1. Clone the candidate's branch
 1. Execute the following:
 
+        bin/bundle
         bin/rails db:drop
         bin/setup
         bin/rspec