Tez 0.7.1 is the first maintenance release on the 0.7.x line and contains over a 100 fixes.

There were 3 incompatible changes introduced:
  TEZ-2679. Admin forms of launch env settings. 
  TEZ-2949. Allow duplicate dag names within session for Tez.
  TEZ-2972. Avoid task rescheduling when a node turns unhealthy

Please see CHANGES.txt for more details.