Add "Support the Development of JUnit" message

[sormuras]

JUnit is maintained by a team of passionate volunteers. Let our users know how to take a chance to give back and support the project -- besides contributing here at GitHub.

Such a message could read as simple as and point to https://steadyhq.com/junit

Thanks for using JUnit 5 -- support its development at https://steadyhq.com/junit

Gradle does something similar: https://travis-ci.org/junit-team/junit5/jobs/485515552#L463-L469

Deliverables

• Decide if we want it
• Decide where we want the message to be emitted
• For example, the JUnit Platform ConsoleLauncher could print such a message
• Decide when and how often the message is displayed: once per version, on each run, after failures are detected...

[sormuras]

in progress...

[sormuras]

Team decision
Always display

Thanks for using JUnit! Support its development at https://junit.org/sponsoring

when the ConsoleLauncher starts, unless the new option --disable-banner is supplied.

[sormuras]

We could split the banner into an intro and outro message. Like:

// INTRO-BANNER: Welcome to JUnit...

>> TREE >>

>> STACKTRACE >>

>> SUMMARY >>
Test run finished after \d+ ms
[         6 containers found      ]
[         0 containers skipped    ]
[         6 containers started    ]
[         0 containers aborted    ]
[         6 containers successful ]
[         0 containers failed     ]
[         8 tests found           ]
[         2 tests skipped         ]
[         6 tests started         ]
[         1 tests aborted         ]
[         3 tests successful      ]
[         2 tests failed          ]

// OUTRO-BANNER: Thanks for using JUnit!
// OUTRO-BANNER: Support its development at https://junit.org/sponsoring

[sormuras]

Ideas for 5.5...

• split message to two lines
• add You can hide this message using --disable-banner
• make the first sentence bold, if ANSI is enabled