Bump poltergeist to 1.6.0

Gemfile

@@ -240,7 +240,7 @@ group :development, :test do
   gem 'ffaker', '~> 2.0.0'
   # PhantomJS driver for Capybara
-  gem 'poltergeist', '~> 1.5.1'
+  gem 'poltergeist', '~> 1.6.0'
   gem 'teaspoon', '~> 1.0.0'
   gem 'teaspoon-jasmine'

Gemfile.lock

@@ -432,7 +432,7 @@ GEM
     parser (2.2.0.2)
       ast (>= 1.1, < 3.0)
     pg (0.15.1)
-    poltergeist (1.5.1)
+    poltergeist (1.6.0)
       capybara (~> 2.1)
       cliver (~> 0.3.1)
       multi_json (~> 1.0)
@@ -708,7 +708,9 @@ GEM
     webmock (1.21.0)
       addressable (>= 2.3.6)
       crack (>= 0.3.2)
-    websocket-driver (0.3.3)
+    websocket-driver (0.5.4)
+      websocket-extensions (>= 0.1.0)
+    websocket-extensions (0.1.2)
     wikicloth (0.8.1)
       builder
       expression_parser
@@ -801,7 +803,7 @@ DEPENDENCIES
   omniauth-twitter
   org-ruby (= 0.9.12)
   pg
-  poltergeist (~> 1.5.1)
+  poltergeist (~> 1.6.0)
   pry-rails
   quiet_assets (~> 1.0.1)
   rack-attack (~> 4.3.0)