Converted test to wd promise chain api.

Did the following:
- Converted all tests to less verbose promise chain syntax
- Added FAST_TESTS=1 mode (It won't work on all device right now, try it on nexus7 api 18, or ios 6.1).
- Added VERBOSE=1 mode which logs wd requests.

Let me know if it is ok, and I'll squash it.