Added the reason parameter to the reserve method
Bumped version to 0.1.2
Added update_resrved_reason method and fixed the lookups
Added show_reserved and show_free methods
Improved the code and changed the behavior and done some tests (and bugs
fixed)

 - Only managed hosts are taken into account
Merge pull request #5 from david-caro/master

Improved the code, adapted the behavior and tested on prod environment