Merge pull request #59 from mxabierto/fix/json_catalog

Fix/json catalog
Records organization activities for dashboard
Changed datasets and distributions count message on inventory preview
Dataset and distribution pluralization to i18n
WIP: Implemented header design with sign in link
Implemented design: Sign in form
Implemented design: Alert when sign in errors
Added design icons to assets
Fix user logs in feature tests
WIP: General dashboard for homepage design
WIP: Organization dashboard sections headers implemented and fix tests
Implemented design: Activity feed in organization dashboard
Added category to activity logs and implemented view more activity logs design
Changed app logo
Implemented design: Inventories list for organization dashboard and pagination
Added footer