Check Flink 1.17 compatibility

[kristoffSC]

Run connector on Flink 1.17
Add build configuration for 1.17
Update Readme.md

In case of bigger issues with 1.15, drop the support for it.

[davidradl]

I tried to compile against 1.17 and 1.18 and get a compile error:

There was an error in the forked process
TestEngine with ID 'junit-jupiter' failed to discover tests

[kristoffSC]

yep, I had exact same thing. Hence the ticket.
I've not spend a lot of time on this one but it seems there is some dependency issue around Junit libs...
Something is drag along with Flink libraries.

[davidradl]

I have run the tests locally at the latest main and see
[ERROR] Tests run: 257, Failures: 3, Errors: 15, Skipped: 0

Inspired byhttps://blog.jetbrains.com/idea/2020/08/migrating-from-junit-4-to-junit-5/ I amended the pom file to use junit5, this allows tests to run at 1.15, 1.16, 1.17, 1.18.0, 1.18.1

at 1.18.1 there are a couple more errors.

[davidradl]

@kristoffSC I have added junit 5 support so the junts run at Flink 1.17 and 1.18.

Note there are errors. I have raised issue #73 for the errors.

[davidradl]

@kristoffSC I see 1.15.0 was failing to build on the pr, but 1.15.3 works. If we drop 1.15 this will not be an issue.
I have added 1.17 and 1.18 to the build file, I think maybe the build machine does not have a enough resources - it seems to be canceling jobs. I see that 1.17 runs and give me the 3 junit errors.

In case it has capacity I have left in 1.16 1.17 and 1.18 . 1.17 fails as expected but the other 2 jobs are cancelled. I wonder if the tests have to complete in a certain time and if they don't then they are cancelled.

[kristoffSC]

Hi,
I think we can drop 1.15 entirely.
Making 1.16 the lowest supported version for now.

16, 17, 18 sounds good.

[davidradl]

@kristoffSC Any idea why the pr build jobs are being cancelled?