Loading tags collection for use with Search

Summary:
Merge branch 'master' of https://github.com/ushahidi/Lamu into posts-search-category

trigger re-render of searchbar when tags are updated

Merge pull request #271 from ushahidi/posts-search-category-fix

Fix for SearchBar not loading tags correctly

Merge branch 'posts-search-category' of https://github.com/ushahidi/Lamu into posts-search-category

Search posts by tags

Merge branch 'master' into posts-search-category

Test Plan: Check for tags loading on search bar then switch between tags and use them to search for posts

Reviewers: rjmackay, shadowhand, seth

Reviewed By: shadowhand, seth

Subscribers: seth

Maniphest Tasks: T120

Differential Revision: https://phabricator.ushahidi.com/D10