Modify dependencies on packages Mailcatcher, Mail, Mine-types to be able...

It should solve issues #806, #870 in Puphpet. It looks that on 2nd July there was changed dependency of Ruby package Mail on Mime-types. Mime-types version 2 and higher requires Ruby 1.9.3. But it looks Mime-types 1.25.1 is enough for Mailcatcher. Fixed and tested and works for me on Ubuntu 12, Ubuntu 14 and CentOS 6.5. Thanks of your advices about this solution.