Fix chrome_options arg being wrong type

Co-authored-by: Dillon Hafer <dillon.hafer@hashrocket.com>

[Fixes #30]

capybara-webmock.gemspec

@@ -32,4 +32,6 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rake", "~> 10.0"
   spec.add_development_dependency "rspec", "~> 3.0"
   spec.add_development_dependency "simplecov"
+  spec.add_development_dependency "sinatra"
+  spec.add_development_dependency "launchy"
 end

lib/capybara/webmock.rb

@@ -68,7 +68,7 @@ def firefox_profile
       end
 
       def chrome_options
-        { args: "proxy-server=127.0.0.1:#{port_number}" }
+        {args: [ "--proxy-server=127.0.0.1:#{port_number}" ]}
       end
 
       def phantomjs_options

spec/capybara/webmock_spec.rb

@@ -1,7 +1,7 @@
 require 'open3'
 require 'fileutils'
 require 'socket'
-
+require 'capybara/spec/spec_helper'
 require 'spec_helper'
 
 describe Capybara::Webmock do
@@ -10,7 +10,7 @@
   end
 
   let(:chrome_args) do
-    Capybara::Webmock.chrome_options[:args]
+    Capybara::Webmock.chrome_options[:args].first
   end
 
   let(:phantomjs_options) do
@@ -22,6 +22,8 @@
   end
 
   describe '#chrome_args' do
+    include Capybara::SpecHelper
+
     it 'has an proxy flag' do
       expect(chrome_args).to include 'proxy-server='
     end
@@ -33,6 +35,15 @@
     it 'has an http proxy port' do
       expect(chrome_args).to include '9292'
     end
+
+    it 'is used by the provided driver' do
+      Capybara.server = :webrick
+      session = Capybara::Session.new(:capybara_webmock_chrome, TestApp)
+
+      expect do
+        session.visit('/')
+      end.not_to raise_error
+    end
   end
 
   describe '#phantomjs_options' do