Fix FutureWarning in plotting by deregistering matplotlib converters …

…(the future behavior). Also fix bad date formatting in non-daily plot that started came with change in matplotlib default in 3.0.2

Merge branch 'master' of github.com:facebook/prophet

Post-release version due to bad package upload

Update README for new version

Make paper link point to PeerJ instead of PDF + update Gems

Add to the changelog / style change.

Initial commit