Don't support nokogiri < 1.8

capybara.gemspec

@@ -20,7 +20,7 @@ Gem::Specification.new do |s|
   s.require_paths = ["lib"]
   s.summary = "Capybara aims to simplify the process of integration testing Rack applications, such as Rails, Sinatra or Merb"
 
-  s.add_runtime_dependency("nokogiri", [">= 1.6.8"])
+  s.add_runtime_dependency("nokogiri", ["~> 1.8"])
   s.add_runtime_dependency("mini_mime", [">= 0.1.3"])
   s.add_runtime_dependency("rack", [">= 1.6.0"])
   s.add_runtime_dependency("rack-test", [">= 0.6.3"])

spec/selector_spec.rb

@@ -116,7 +116,6 @@ RSpec.describe Capybara do
         end
 
         it "works with 'special' characters" do
-          skip "We support old Nokogiris but they have their limits" if Gem::Version.new(Nokogiri::VERSION) < Gem::Version.new('1.6.8')
           expect(string.find(:custom_css_selector, "div", id: "#special")[:id]).to eq '#special'
           expect(string.find(:custom_css_selector, "input", id: "2checkbox")[:id]).to eq '2checkbox'
         end
@@ -129,7 +128,6 @@ RSpec.describe Capybara do
         end
 
         it "works with 'special' characters" do
-          skip "We support old Nokogiris but they have their limits" if Gem::Version.new(Nokogiri::VERSION) < Gem::Version.new('1.6.8')
           expect(string.find(:custom_css_selector, "input", class: ".special")[:id]).to eq 'file'
           expect(string.find(:custom_css_selector, "input", class: "2checkbox")[:id]).to eq '2checkbox'
         end