Remove unnecessary spec_helper requires.

These cuke scenarios don't create a spec_helper file.
Instead, the `spec/spec_helper` file (used by rspec-expectations'
specs, but not intended for use by the cukes) was being loaded.
It was causing failures because it disables `should` but I hadn't
gone through the cukes yet.

features/built_in_matchers/equality.feature

@@ -31,8 +31,6 @@ Feature: equality matchers
   Scenario: compare using eq (==)
     Given a file named "compare_using_eq.rb" with:
       """ruby
-      require 'spec_helper'
-
       describe "a string" do
         it "is equal to another string of the same value" do
           "this string".should eq("this string")
@@ -55,8 +53,6 @@ Feature: equality matchers
   Scenario: compare using ==
     Given a file named "compare_using_==.rb" with:
       """ruby
-      require 'spec_helper'
-
       describe "a string" do
         it "is equal to another string of the same value" do
           "this string".should == "this string"
@@ -79,8 +75,6 @@ Feature: equality matchers
   Scenario: compare using eql (eql?)
     Given a file named "compare_using_eql.rb" with:
       """ruby
-      require 'spec_helper'
-
       describe "an integer" do
         it "is equal to another integer of the same value" do
           5.should eql(5)
@@ -102,8 +96,6 @@ Feature: equality matchers
   Scenario: compare using equal (equal?)
     Given a file named "compare_using_equal.rb" with:
       """ruby
-      require 'spec_helper'
-
       describe "a string" do
         it "is equal to itself" do
           string = "this string"
@@ -126,8 +118,6 @@ Feature: equality matchers
   Scenario: compare using be (equal?)
     Given a file named "compare_using_be.rb" with:
       """ruby
-      require 'spec_helper'
-
       describe "a string" do
         it "is equal to itself" do
           string = "this string"