Fixed the version range for sinon-chai.
Update gestures.md

Documented how to interact with slider on Android
improved touch test + wd upgrade
Merge pull request #2280 from joe-harter/master

Update gestures.md per Issue #2254
Merge pull request #2278 from paymand/chai

Fixed the version range for sinon-chai.
Merge pull request #2279 from sebv/touch-test

improved touch test + wd upgrade
these methods take complex body parameters, so make them posts