Write out sham_rack gem

This means we have one less Net::HTTP monkeypatch.

sham_rack cannot handle IPv6 addresses which means it breaks Net::HTTP
connections because it monkey-patches Net::HTTP

Gemfile

@@ -388,7 +388,6 @@ group :test do
   gem 'json-schema', '~> 2.8.0'
   gem 'webmock', '~> 3.5.1'
   gem 'rails-controller-testing'
-  gem 'sham_rack', '~> 1.3.6'
   gem 'concurrent-ruby', '~> 1.1'
   gem 'test-prof', '~> 0.2.5'
   gem 'rspec_junit_formatter'

Gemfile.lock

@@ -884,8 +884,6 @@ GEM
       faraday (>= 0.7.6, < 1.0)
     settingslogic (2.0.9)
     sexp_processor (4.12.0)
-    sham_rack (1.3.6)
-      rack
     shoulda-matchers (4.0.1)
       activesupport (>= 4.2.0)
     sidekiq (5.2.7)
@@ -1232,7 +1230,6 @@ DEPENDENCIES
   selenium-webdriver (~> 3.141)
   sentry-raven (~> 2.9)
   settingslogic (~> 2.0.9)
-  sham_rack (~> 1.3.6)
   shoulda-matchers (~> 4.0.1)
   sidekiq (~> 5.2.7)
   sidekiq-cron (~> 1.0)

spec/lib/container_registry/blob_spec.rb

@@ -116,7 +116,7 @@ describe ContainerRegistry::Blob do
         let(:location) { 'file:///etc/passwd' }
 
         it 'raises an error' do
-          expect { blob.data }.to raise_error(ArgumentError, 'invalid address')
+          expect { blob.data }.to raise_error(NoMethodError, %q{undefined method `request_uri' for #<URI::File file:///etc/passwd>})
         end
       end
     end

spec/services/projects/download_service_spec.rb

@@ -20,13 +20,8 @@ describe Projects::DownloadService do
 
     context 'for URLs that are on the whitelist' do
       before do
-        sham_rack_app = ShamRack.at('mycompany.fogbugz.com').stub
-        sham_rack_app.register_resource('/rails_sample.jpg', File.read(Rails.root + 'spec/fixtures/rails_sample.jpg'), 'image/jpg')
-        sham_rack_app.register_resource('/doc_sample.txt', File.read(Rails.root + 'spec/fixtures/doc_sample.txt'), 'text/plain')
-      end
-
-      after do
-        ShamRack.unmount_all
+        stub_request(:get, 'http://mycompany.fogbugz.com/rails_sample.jpg').to_return(body: File.read(Rails.root + 'spec/fixtures/rails_sample.jpg'))
+        stub_request(:get, 'http://mycompany.fogbugz.com/doc_sample.txt').to_return(body: File.read(Rails.root + 'spec/fixtures/doc_sample.txt'))
       end
 
       context 'an image file' do