Fix tests

NoMethodError:
  undefined method `file_fixture'

Author: ackintosh

kubernetes/spec/helpers/file_fixtures.rb

@@ -31,6 +31,6 @@ def file_fixture(fixture_name)
       end
     end
 
-    extend FileFixtures
+    Object.include FileFixtures
   end
 end

kubernetes/spec/spec_helper.rb

@@ -12,6 +12,7 @@
 
 # load the gem
 require 'kubernetes'
+require 'helpers/file_fixtures'
 
 # The following  was generated by the `rspec --init` command. Conventionally, all
 # specs live under a `spec` directory, which RSpec adds to the `$LOAD_PATH`.