Improve readme for JUnit

[mleegwt]

Currently the examples in the readme only use JUnit 4. JUnit 5 is not mentioned at all.
I would suggest to choose one of the following options:

• Add JUnit 5 support
• Add JUnit 5 support and reduce visibility of JUnit 4 by only linking to the JUnit 4 examples.
• Replace JUnit 4 by JUnit 5 examples and not mention JUnit 4 at all

What is the best option?

[dajudge]

Hi @mleegwt,

thanks for bringing this up!

Indeed it's about time to have JUnit 5 docs available. I'd probably go for having both variants on the README with the JUnit 5 version coming first.

WDYT?

[mleegwt]

Hi @dajudge,

Sounds like a great option!

[dajudge]

Would you be interested in making a contribution to the README along those lines?