NSFE: diktat-rules\src\test\resources\test\paragraph2\header when running mvn test from diktat-rules/

[0x6675636b796f75676974687562]

The approach used in diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/generation/Generation.kt will work if Maven is invoked from the project root, e. g.:

$ mvn test

or

$ mvn -pl diktat-rules test

Yet, a quite legitimate scenario (particularly, used by IDEA when creating Maven run configurations) is invoking a Maven goal from the module directory, e. g.:

cd diktat-rules/ && mvn test

In this latter case, Maven execution will fail with:

java.nio.file.NoSuchFileException: diktat-rules\src\test\resources\test\paragraph2\header
    at sun.nio.fs.WindowsException.translateToIOException (WindowsException.java:79)
    at sun.nio.fs.WindowsException.rethrowAsIOException (WindowsException.java:97)
    at sun.nio.fs.WindowsException.rethrowAsIOException (WindowsException.java:102)
    at sun.nio.fs.WindowsDirectoryStream.<init> (WindowsDirectoryStream.java:86)
    at sun.nio.fs.WindowsFileSystemProvider.newDirectoryStream (WindowsFileSystemProvider.java:518)
    at java.nio.file.Files.newDirectoryStream (Files.java:457)
    at java.nio.file.Files.list (Files.java:3451)
    at org.cqfn.diktat.ruleset.generation.GenerationKt.validateYear (Generation.kt:67)
    at org.cqfn.diktat.ruleset.generation.GenerationKt.main (Generation.kt:36)
    at org.cqfn.diktat.ruleset.generation.GenerationKt.main (Generation.kt)
    at org.codehaus.mojo.exec.ExecJavaMojo$1.run (ExecJavaMojo.java:254)
    at java.lang.Thread.run (Thread.java:750)

Originally posted by @0x6675636b796f75676974687562 in #1296 (comment)