add context to share data between interceptors

[JiaLiPassion]

Based on #50, add a context to share data between interceptors, to keep the current interface unchange, use a interceptorZone to share data.

to set data in context.

  let interceptor = (data, method, context) => { 
        if (context) context['key'] = 'value';
        return data;
    }

    let otherInterceptor = (data, method, context) => { 
        if (context) let sharedData = context['key'];
        return data;
    }

[codecov-io]

Current coverage is 100% (diff: 100%)

Merging #92 into master will not change coverage

@@           master   #92   diff @@
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  Files          13    13          
  Lines         179   180     +1   
  Methods        42    42          
  Messages        0     0          
  Branches       25    25          
===================================
+ Hits          179   180     +1   
  Misses          0     0          
  Partials        0     0          

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[JiaLiPassion]

Sorry for the late reply, I didn't receive the email notification, I have make the change, and please review, thank you.