Inconsistencies in Hello World - Tutorial.md

[foundingnimo]

Tutorial.md in Hello world has diverged from the code.

1. It says the test fails with org.junit.ComparisonFailure: expected:<[Hello, World!]> but was:<[]> but actual failure is
   org.junit.ComparisonFailure: expected:<[Hello, World]!> but was:<[Goodbye, Mars]!>

2. It says the :compileKotlin task should emit a warning:
   w: /Users/jtigger/exercism/exercises/kotlin/hello-world/src/main/kotlin/HelloWorld.kt: (1, 11): Parameter 'name' is never used

But that parameter isn't actually in the fun declaration

3. It says that hello() returns "" - but it actually returns Goodbye, Mars!