Fixes Issue #89 - Hanlon log files are not re-created once deleted at runtime

Logger gem is creating logger device only at the time of initializing leading to the issue of writing to a null device if log file is deleted after starting the server. This is fixed by monkey patching the add method of logger gem which forces the file to re-create. However the complete behavior could be tested at the server end as most of the Hanlon logging happens at cli end as described in Issue #113