Release v3.8.0

Merge remote-tracking branch 'origin/develop' into uchaguzi-2017

Merge pull request ushahidi#2200 from ushahidi/develop

New release for Uchaguzi containing all changes

Merge branch 'develop' of github.com:ushahidi/platform into uchaguzi-…

…2017

Merge pull request ushahidi#2181 from ushahidi/feature/contact-hydrat…

…ion-csv-export

Adding contact hydration to CSV export

Updating lock hydration to respect standard format

merge develop

Merge pull request ushahidi#2103 from ushahidi/feature/Post_Locking

Adding Post Locks to Post attribute

Updating filtering posts

Post filtering