Added `utc_offset` to device info. Fixes IOS-466.
Added `utc_offset` to device info.
Fixes IOS-466.

apptentive/apptentive-ios,Jawbone/apptentive-ios,hibu/apptentive-ios,hibu/apptentive-ios,Jawbone/apptentive-ios,ALHariPrasad/apptentive-ios,apptentive/apptentive-ios,sahara108/apptentive-ios,hibu/apptentive-ios,sahara108/apptentive-ios,apptentive/apptentive-ios,ALHariPrasad/apptentive-ios