Properly export the minimum supported Jenkins version

[PierreBtz]

Fixes #257 .

What happened is that when generating the pom.properties, the Maven Archiver plugin is not exactly working as one might expect (see sources).
So we cannot really rely on the pom.properties, IMHO we don't need to export the whole properties of the pom, so simply using the resource plugin filtering a new property file should answer the need.

After the fix:

$ java -jar app/target/jenkinsfile-runner-standalone.jar -jv 2.204.5
Jenkins version [2.204.5] not suported by this jenkinsfile-runner version (requires 2.235.2).

java -jar app/target/jenkinsfile-runner-standalone.jar --version
1.0-beta-15-SNAPSHOT

[oleg-nenashev]

Thanks for the patch! I have to admit that I have not tested this scenario on real cases, because the version is managed differently there. The fix looks right