0.3.9

What's Changed

• build: Don't branch or tag this in the named release by @kdmccormick in #243
• fix: Add author field to ContentSerializer for Forums V2 API compatibility by @blarghmatey in #245
• fix: threads/comments timestamp not correct by @taimoor-ahmed-1 in #262
• bugfix: Fix Mongo contents queries when content_type is unset by @rehmansheikh222 in #265
• bugfix: use string thread IDs for read_states lookup in MySQL backend by @rehmansheikh222 in #266