[WIP] Create PHP configuration test support.

Hi, Mr. mizzy.

Thank you very much for your time at hbstudy#45.

I'm added PHP configuration check. However, There is no confidence in testcode.
When you have a time, please check this testcode. Then please advice for me.

Thanks.

Yuichiro Saito (@koemu)


Note: Usage

    describe php_config('memory_limit') do
      it { should match_ini_value '128M' }
    end