restore spec helper
start writing spec for keword api
Finished api wrapping of account,campaign,group,keyword, creative along with corresponding test
Finished report and corresponding test
Finished: Account, Plan, Group, Keyword, Creative and corresponding test. Test of Update in Creative fail.
change module to class;and process function and implement account&keyword
extract test to method process
增加make_type，reverse_type方法用于进行ppcapi和搜索引擎api之间的转换；另有其他api的调整
完成百度api的包裹，各个功能实现完全
change Operation::call to eval, to adapt to class methods and inner class
少许修改
initialize
delete sensitive info