Perform the where(...).first to find_by(...) refactoring.

This refactoring was automated using the command: bundle exec "ruby refactorings/where_dot_first_to_find_by/app.rb"

spec/controllers/session_controller_spec.rb

@@ -171,7 +171,7 @@ describe SessionController do
 
     context 'when email is confirmed' do
       before do
-        token = user.email_tokens.where(email: user.email).first
+        token = user.email_tokens.find_by(email: user.email)
         EmailToken.confirm(token.token)
       end