JUnit5BestPractices - OpenReWrite Recipe

[mjd507]

hello team,

I just want to contribute more to open source, and I found unit test may be a easy entrypoint for me.

currently I found we can futher improve our test cases by OpenReWrite Junit5.

I do a quick open-rewrite case for spring-integration-mail.

can team review and suggest is this looks good?

if so, I would very happy to do others modules one by one.

[artembilan]

Please, open Pull Request for those spring-integration-mail module and we will go from there.
Thanks.