Initial mobile context
 - Fixes #1
Update README.md
Added in the missing Release 2
Advertising ID for Android added

- Fixes #21
- cc @alexanderdean
Renamed deviceVendor to deviceManufacturer
Added appleIdfv (ID for vendor)
Fixed the required fields, will need reuploading to Iglu Central /cc @yalisassoon
Merge branch 'feature/mobile_context'

Conflicts:
	README.md