Bump capybara from 2.14.0 to 2.18.0

Bumps [capybara](https://github.com/teamcapybara/capybara) from 2.14.0 to 2.18.0.
- [Release notes](https://github.com/teamcapybara/capybara/releases)
- [Changelog](https://github.com/teamcapybara/capybara/blob/master/History.md)
- [Commits](teamcapybara/capybara@2.14.0...2.18.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Gemfile

@@ -54,7 +54,7 @@ group :development, :test do
   gem 'sass-rails', '~> 5.0.5' # locked
   gem 'coffee-rails', '~> 4.2.1'
   gem 'pry', '~> 0.10.4'
-  gem 'capybara', '~> 2.14.0'
+  gem 'capybara', '~> 2.18.0'
   gem 'selenium-webdriver', '3.4.0'
   gem 'launchy', '~> 2.4.3'
   gem "minitest", '~> 5.10.2'

Gemfile.lock

@@ -67,7 +67,8 @@ GEM
       minitest (~> 5.1)
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    addressable (2.4.0)
+    addressable (2.5.2)
+      public_suffix (>= 2.0.2, < 4.0)
     airbrussh (1.2.0)
       sshkit (>= 1.6.1, != 1.7.0)
     arel (6.0.4)
@@ -107,13 +108,13 @@ GEM
     capistrano-rbenv (2.1.1)
       capistrano (~> 3.1)
       sshkit (~> 1.3)
-    capybara (2.14.0)
+    capybara (2.18.0)
       addressable
-      mime-types (>= 1.16)
+      mini_mime (>= 0.1.3)
       nokogiri (>= 1.3.3)
       rack (>= 1.0.0)
       rack-test (>= 0.5.4)
-      xpath (~> 2.0)
+      xpath (>= 2.0, < 4.0)
     childprocess (0.5.6)
       ffi (~> 1.0, >= 1.0.11)
     cliver (0.3.2)
@@ -261,14 +262,15 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.8.1)
       slop (~> 3.4)
+    public_suffix (3.0.2)
     qa (1.1.0)
       activerecord-import
       deprecation
       faraday
       nokogiri (~> 1.6)
       rails (>= 4.2.0, < 6.0)
       rdf
-    rack (1.6.8)
+    rack (1.6.10)
     rack-dev-mark (0.7.5)
       rack (>= 1.1)
     rack-test (0.6.3)
@@ -428,8 +430,8 @@ GEM
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.2)
     xml-simple (1.1.5)
-    xpath (2.0.0)
-      nokogiri (~> 1.3)
+    xpath (3.1.0)
+      nokogiri (~> 1.8)
 
 PLATFORMS
   ruby
@@ -445,7 +447,7 @@ DEPENDENCIES
   capistrano-bundler (~> 1.2.0)
   capistrano-rails (~> 1.2.3)
   capistrano-rbenv (~> 2.1.1)
-  capybara (~> 2.14.0)
+  capybara (~> 2.18.0)
   coffee-rails (~> 4.2.1)
   coveralls (= 0.8.21)
   devise (~> 3.5.5)