remove Run method from TF interface about go-testdeep

[maxatome]

I like the idea, let me test on my side :) Thanks for the report.

[maxatome]

Done in tb branch.
I replaced the td.TestingFT interface by testing.TB as you suggested and RunT() method correctly delegates to any T.Run(string, func(T)) bool method.
I need to sleep a little to check all is OK: shouldn't I keep td.TestingFT as an alias of testing.TB instead?
Anyway, this Run() function bored me for a long time, thank you for pushing me to enhance this part. :)

[rogpeppe]

Thanks for doing this!

A good reason to keep testing.FT around as an alias would be to preserve backward compatibility, but since you would already be breaking compatibility by removing the Run method, maybe that's not worth doing. It depends a bit on how you see the maturity of this module and how many existing importers you think the change might break.

[maxatome]

Done in #100 + v1.6.0 release.

I ended up choosing to let testing.FT interface as a deprecated alias on testing.TB.

Thanks!