tag groups
renamed to just 'Taggable'
Merge pull request #28 from aweiteka/tag_mixin

tag groups, taggable mixin, unit tests
removed credentials.yaml, new credentials.yaml.template, updated gitignore
Merge pull request #29 from aweiteka/master
Refactor details region
Merge pull request #31 from bcrochet/details_region

Refactor details region