Skip forking spec on JRuby

* JRuby doesn't support `fork`, so this test is irrelevant.

Gemfile.lock

@@ -21,8 +21,10 @@ GEM
       ffi (~> 1.0, >= 1.0.11)
     diff-lcs (1.2.4)
     ffi (1.9.0)
+    ffi (1.9.0-java)
     ffi (1.9.0-x86-mingw32)
     json (1.8.1)
+    json (1.8.1-java)
     mime-types (2.0)
     mini_magick (3.2.1)
       subexec (~> 0.0.4)
@@ -30,6 +32,10 @@ GEM
     multi_json (1.7.8)
     nokogiri (1.6.0)
       mini_portile (~> 0.5.0)
+    nokogiri (1.6.0-java)
+      mini_portile (~> 0.5.0)
+    nokogiri (1.6.0-x86-mingw32)
+      mini_portile (~> 0.5.0)
     rack (1.5.2)
     rack-protection (1.3.2)
       rack
@@ -61,6 +67,7 @@ GEM
       nokogiri (~> 1.3)
 
 PLATFORMS
+  java
   ruby
   x86-mingw32
 

gemfiles/2.0.gemfile.lock

@@ -22,12 +22,15 @@ GEM
       ffi (~> 1.0, >= 1.0.11)
     diff-lcs (1.2.5)
     ffi (1.9.0)
+    ffi (1.9.0-java)
     json (1.8.1)
+    json (1.8.1-java)
     mime-types (1.23)
     mini_magick (3.5.0)
       subexec (~> 0.2.1)
     multi_json (1.7.8)
     nokogiri (1.5.9)
+    nokogiri (1.5.9-java)
     rack (1.5.2)
     rack-protection (1.3.2)
       rack
@@ -59,6 +62,7 @@ GEM
       nokogiri (~> 1.3)
 
 PLATFORMS
+  java
   ruby
 
 DEPENDENCIES

gemfiles/2.1.gemfile.lock

@@ -21,12 +21,15 @@ GEM
       ffi (~> 1.0, >= 1.0.11)
     diff-lcs (1.2.5)
     ffi (1.9.0)
+    ffi (1.9.0-java)
     json (1.8.1)
+    json (1.8.1-java)
     mime-types (1.23)
     mini_magick (3.5.0)
       subexec (~> 0.2.1)
     multi_json (1.7.8)
     nokogiri (1.5.9)
+    nokogiri (1.5.9-java)
     rack (1.5.2)
     rack-protection (1.3.2)
       rack
@@ -58,6 +61,7 @@ GEM
       nokogiri (~> 1.3)
 
 PLATFORMS
+  java
   ruby
 
 DEPENDENCIES

spec/browser_spec.rb

@@ -148,7 +148,7 @@ describe Capybara::Webkit::Browser do
     end
   end
 
-  describe "forking", :skip_on_windows => true do
+  describe "forking", skip_on_windows: true, skip_on_jruby: true do
     it "only shuts down the server from the main process" do
       browser.reset!
       pid = fork {}

spec/spec_helper.rb

@@ -25,6 +25,7 @@ end
 
 RSpec.configure do |c|
   c.filter_run_excluding :skip_on_windows => !(RbConfig::CONFIG['host_os'] =~ /mingw32/).nil?
+  c.filter_run_excluding :skip_on_jruby => !defined?(::JRUBY_VERSION).nil?
   Capybara::SpecHelper.configure(c)
 end