(#2) Add support for Http adapter on Node.js

There is one issue left.   `npm run coverage`  fails because I use use string representation of function(`getText` and `isFiltered`) when I build the design couchdb design document.  With coverage, there is code injected in each function, such as `__cov_ty1IsRMbY5smuJSV2MiTeQ.f['4']++;__cov_ty1IsRMbY5smuJSV2MiTeQ.s['16']++;`, which make lead to couchdb index function failure.    

I'm not sure about the right solution.  Exclude Http test from coverage ?   Workaround some how ?