Updates to README, licence file and gemspec and created Travis-CI configuration

* Renames README.rdoc to README.md and adds Travis-CI badges
* Renames MIT-LICENSE to LICENSE and fixes up name
* Fixes up gemspec
* Adds Travis-CI configuration file
* Adds db directory to keep Travis-CI happy
Adds new models Manufacturer and Widget to dummy app
Define Mixins::InitializableAttributes inline for time being