unknown method 'normalize_params' when running cucumber test

[NickSchimek]

This is the error when trying to run the guess.feature test:

➜  hw-sinatra-saas-hangperson git:(master) ✗ cucumber features/guess.feature:7
Feature: guess correct letter

  As a player playing Hangperson
  So that I can make progress toward the goal
  I want to see when my guess is correct

  Scenario: guess correct letter that occurs once # features/guess.feature:7
    Given I start a new game with word "garply"   # features/step_definitions/game_steps.rb:12
    When I guess "r"                              # features/step_definitions/game_steps.rb:19
      undefined method `normalize_params' for Rack::Utils:Module (NoMethodError)
      ./features/step_definitions/game_steps.rb:22:in `/^I guess "(.*)"(?: again)?$/'
      features/guess.feature:10:in `When I guess "r"'
    Then I should see "r" within "span.word"      # features/step_definitions/game_steps.rb:71

Failing Scenarios:
cucumber features/guess.feature:7 # Scenario: guess correct letter that occurs once

1 scenario (1 failed)
3 steps (1 failed, 1 skipped, 1 passed)
0m0.050s
Coverage report generated for Cucumber Features to /Users/miafro/Documents/edx/saasbook/hw-sinatra-saas-hangperson/coverage. 43 / 61 LOC (70.49%) covered.

This seems to be an issue related to the click_button method in the game_steps.rb file.

SOLUTION FOUND: Updating to the latest Capybara release 2.16.1 fixed the issue for me.
Has anyone else seen this issue?