Berlin HF Tests Submodule Update Planning

[holgerd77]

To get this ready to the coming Berlin tests I would do the following:

• Do a version v1.3.1 release here with the current develop branch from ethereum/tests to have some work basis for first integration tests on the VM side
• Collect experiences / focus discussion on potential test format changes here, will also reference this issue in the v1.3.1 release notes
• I would along try to work towards a v8.0.0-beta.1 Berlin HF tagged release on the ethereum/tests side, see v7.0.0-beta.1 release for comparison
• Once we have a fully Berlin compatible release over there we can do a v1.4.0 version here, release and further integrate on the VM side

[evertonfraga]

You did a great job on v7 release description, saving me quite some time :)