Implements tests for tasks

[askz]

Hi,

This is obviously related to #70;

I have no idea how to implement these tests (and haven't searched yet) but would really want to help!

[frol]

Yeah... I have no idea how to implement this either :(

I will think of a way to implement this over weekend.

[frol]

Well, it seems that commands testing can be a part of integrational testing, which is not implemented yet.