Don't run em-http-request tests on travis on 1.8.6.

On travis, we're getting a weird error like:

ruby: symbol lookup error: /home/travis/.rvm/gems/ruby-1.8.6-p420/gems/em-http-request-0.3.0/lib/http11_client.so: undefined symbol: rb_hash_lookup

Rakefile

@@ -33,6 +33,7 @@ task :default => [:spec, :cucumber]
 namespace :ci do
   desc "Sets things up for a ci build on travis-ci.org"
   task :setup do
+    ENV['TRAVIS'] = 'true'
     sh "git submodule init"
     sh "git submodule update"
   end

cucumber.yml

@@ -7,6 +7,10 @@ interp_opts = if defined?(RUBY_ENGINE)
 else
   ''
 end
+
+if ENV['TRAVIS'] && RUBY_VERSION == '1.8.6'
+  interp_opts << ' --tags ~@exclude-travis-186'
+end
 %>
 default: <%= std_opts %><%= interp_opts %> features
 wip: --tags @wip:30 --wip features<%= interp_opts %>

features/http_libraries/em_http_request.feature

@@ -1,4 +1,4 @@
-@exclude-jruby @exclude-rbx
+@exclude-jruby @exclude-rbx @exclude-travis-186
 Feature: EM HTTP Request
 
   EM HTTP Request allows multiple simultaneous asynchronous requests.

features/support/http_lib_filters.rb

@@ -22,6 +22,8 @@ def cell_values
 elsif RUBY_PLATFORM == 'java'
   # These gems have C extensions and can't install on JRuby.
   UNSUPPORTED_HTTP_LIBS = %w[ typhoeus patron curb em-http-request ]
+elsif RUBY_VERSION == '1.8.6' && ENV['TRAVIS']
+  UNSUPPORTED_HTTP_LIBS = %w[ em-http-request ]
 end
 
 if defined?(UNSUPPORTED_HTTP_LIBS)

spec/support/shared_example_groups/http_library.rb

@@ -7,7 +7,15 @@
     raise ArgumentError.new("No http library adapter module could be found for #{library}")
   end
 
-  describe "using #{adapter_module.http_library_name}", :unless => (RUBY_INTERPRETER != :mri && library =~ /(typhoeus|curb|patron|em-http)/) do
+  http_lib_unsupported = if RUBY_INTERPRETER == :mri
+    # em-http-request is causing issues on 1.8.6 on travis like:
+    # ruby: symbol lookup error: /home/travis/.rvm/gems/ruby-1.8.6-p420/gems/em-http-request-0.3.0/lib/http11_client.so: undefined symbol: rb_hash_lookup
+    library =~ /em-http/ && RUBY_VERSION == '1.8.6' && ENV['TRAVIS']
+  else
+    library =~ /(typhoeus|curb|patron|em-http)/
+  end
+
+  describe "using #{adapter_module.http_library_name}", :unless => http_lib_unsupported do
     include adapter_module
 
     # Necessary for ruby 1.9.2.  On 1.9.2 we get an error when we use super,