set git user.email config if unset (fix tests running on travis)
set git user.email config if unset (fix tests running on travis)

eyeye/yotta,stevenewey/yotta,ntoll/yotta,ARMmbed/yotta,iriark01/yotta,autopulated/yotta,theotherjimmy/yotta,eyeye/yotta,iriark01/yotta,ARMmbed/yotta,ntoll/yotta,bridadan/yotta,stevenewey/yotta,bridadan/yotta,autopulated/yotta,BlackstoneEngineering/yotta,BlackstoneEngineering/yotta,theotherjimmy/yotta