Force version number to be a string

Prevents accidental parsing as float, e.g. 7.1
Do not specify a default browser

Allows us to support iPad bug workaround.
See
https://support.saucelabs.com/entries/50675504-iOS-Desired-Capabilities
Support 'deviceName' parameter
Support 'device-orientation' parameter
Merge branch 'feat-mobile-device-support'

Fixes and features necessary for iOS, et al. testing.