Put Logger-Tests into test module
Put Logger-Tests into test module

The Rust Book[1][] states, that the idiomatic way to use tests is to
define a test module. This also removes the "ugly" use-include inside a
function.

[1]: http://doc.rust-lang.org/1.0.0-beta.3/book/testing.html#the-test-module

Drakulix/zwreec,Drakulix/zwreec