Add functional test for shell_out_with_systems_locale
user
```ruby
#
# Copyright:: Copyright (c) 2014 Chef Software, Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

require 'spec_helper'

describe Chef::Mixin::ShellOut do
  include Chef::Mixin::ShellOut

  describe "shell_out_with_systems_locale" do
    describe "when environment['LC_ALL'] is not set" do
      it "should use the default shell_out setting" do
        cmd = if windows?
          shell_out_with_systems_locale('echo %LC_ALL%')
        else
          shell_out_with_systems_locale('echo $LC_ALL')
        end

        # From mixlib-shellout/lib/mixlib/shell_out.rb:
        #
        # * +environment+: a Hash of environment variables to set before the command
        # is run. By default, the environment will *always* be set to 'LC_ALL' => 'C'
        # to prevent issues with multibyte characters in Ruby 1.8. To avoid this,
        # use :environment => nil for *no* extra environment settings, or
        # :environment => {'LC_ALL'=>nil, ...} to set other environment settings
        # without changing the locale.
        cmd.stdout.chomp.should eq 'C'
      end
    end

    describe "when environment['LC_ALL'] is set" do
      it "should use the option's setting" do
        cmd = if windows?
          shell_out_with_systems_locale('echo %LC_ALL%', :environment => {'LC_ALL' => 'POSIX'})
        else
          shell_out_with_systems_locale('echo $LC_ALL', :environment => {'LC_ALL' => 'POSIX'})
        end

        cmd.stdout.chomp.should eq 'POSIX'
      end
    end
  end
end
```
assistant