[EPIC] Release of 0.9.0

[jerqi]

Describe the proposal

Release of 0.9.0

Task list

• [ ] Make all PR about 0.9.0 are merged
• [x] Branch cut
• [ ] The new version test
• [ ] Prepare release candiate
• [ ] Vote for new version in dev mail list
• [ ] Vote for new version in incubator mail list