[fix bug 1003138] Use timezone aware objects on Announcement.published.
put the right location for stage

put the right location for stage
Merge pull request #937 from Sheeri/patch-11

put the right location for stage
Merge pull request #935 from glogiotatidis/ann

[fix bug 1003138] Use timezone aware objects on Announcement.published.
Add separate model for vouches and migrate data