refactor for async wrapper without updating tests
intermediate commit. Webrequest related tests are fixed for async wrapper
fixed more tests
tests passing for async wrapper refactoring
fix constants for sample
update for review comments. Set http.keepAlive to false
update for review comments and fix one failing test
update travis
merge from dev
update for review comment
Merge pull request #48 from MSOpenTech/dev_async_cache

Dev async cache