More tests added ...

Signed-off-by: Krzysztof Wilczynski <krzysztof.wilczynski@linux.com>
Merge branch 'master' of github.com:kwilczynski/go-magic
Merge branch 'master' of github.com:kwilczynski/go-magic
Small re-factor.

Signed-off-by: Krzysztof Wilczynski <krzysztof.wilczynski@linux.com>