对Mob的Share进行简易封装
使用pod集成，导入以下框架就行了
pod 'ShareSDK3'
pod 'ShareSDK3/ShareSDKPlatforms/QQ'
pod 'ShareSDK3/ShareSDKPlatforms/SinaWeibo'
pod 'ShareSDK3/ShareSDKPlatforms/WeChat'
pod 'ShareSDK3/ShareSDKUI'
pod 'MOBFoundation'