Change string to something actually in the page

scraper.rb

@@ -7,7 +7,7 @@
 # Check that mitmproxy gives a working certificate for SSL connections
 # If the certificate isn't valid it should throw an exception
 open("https://morph.io") do |f|
-  raise "Unexpected result" unless f.read.include?("Take the hassle out of web scraping")
+  raise "Unexpected result" unless f.read.include?("Hassle-free web scraping.")
 end
 # Check that output streaming works (in which case you should see each line one second apart
 # rather than getting all the lines at the end)