Install rspec

Gemfile

 # frozen_string_literal: true
 
 source 'https://rubygems.org'
-
 git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }
 
-# gem "rails"
-
+gem 'dotenv', '~> 2.7'
 gem 'httparty', '~> 0.18.0'
-
 gem 'nokogiri', '~> 1.10'
-
 gem 'pg', '~> 1.2'
-
+gem 'rack', '~> 2.2'
+gem 'rake', '~> 13.0'
+gem 'rspec', '~> 3.9'
+gem 'sassc', '~> 2.2'
 gem 'sequel', '~> 5.30'
-
 gem 'sinatra', '~> 2.0'
-
-gem 'dotenv', '~> 2.7'
-
-gem 'sassc', '~> 2.2'
-
-gem 'rake', '~> 13.0'
-
-gem 'rack', '~> 2.2'

Gemfile.lock

 GEM
   remote: https://rubygems.org/
   specs:
+    diff-lcs (1.3)
     dotenv (2.7.5)
     ffi (1.12.2)
     httparty (0.18.0)
     rack-protection (2.0.8.1)
       rack
     rake (13.0.1)
+    rspec (3.9.0)
+      rspec-core (~> 3.9.0)
+      rspec-expectations (~> 3.9.0)
+      rspec-mocks (~> 3.9.0)
+    rspec-core (3.9.1)
+      rspec-support (~> 3.9.1)
+    rspec-expectations (3.9.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.9.0)
+    rspec-mocks (3.9.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.9.0)
+    rspec-support (3.9.2)
     ruby2_keywords (0.0.2)
     sassc (2.2.1)
       ffi (~> 1.9)
   pg (~> 1.2)
   rack (~> 2.2)
   rake (~> 13.0)
+  rspec (~> 3.9)
   sassc (~> 2.2)
   sequel (~> 5.30)
   sinatra (~> 2.0)