support for java 11 and 17 at build time

[mosidev]

• spock framework needs to be updated and because of that the junit needs to changed to junit-vintage
• maven surefire version needs to be updated in the jxls module
• maven source and javadoc plugins needs to be updated
• to sync mockito and cglib versions between maven and gradle they should be updated
• java 8 ZonedDateTime return time with millisecond and java 11+ return time with nanosecond, so the JSR310Test.testInstant() unit test needs to be changed to work with java 8 and above

For these changes, the minimum version of Java does not need to be updated and version 8 will remain.

[SoltauFintel]

a) I don't know Java higher than version 8. Which JDK are you using? (exact name+version)

b) What is the difference between JUnit 4 and JUnit Vintage 5?

c) Actually we want to get rid of the spock based test cases. (Who wants to change them?)

d) I have the impression that only src/test is affected. I have to test whether everything still works for me (with Gradle)... leonate would have to check that with Maven.

[mosidev]

a) I'm using the Oracle JDK and tested my changes with Oracle JDK 8, 11 and 17

b) JUnit Vintage is the Junit 5 implementation of Junit 4 api. the latest version of spock framework didn't work with Junit 4.

[SoltauFintel]

see PR #179
and #212

[SoltauFintel]

closed, as PR is already merged