Bump version: 2.8.0 → 2.8.1 

Bump version: 2.7.0 → 2.8.0 

Bump version: 2.6.0 → 2.7.0 (#790) 

Update Changelog for v2.6.0 (#739) * Update Changelog for v2.6.0 * Bump version: 2.5.0 → 2.6.0

Bump version: v2.4.0 → v2.5.0 

Bump version: v2.3.0 → v2.4.0 

Bump version: v2.2.1 → v2.3.0 

Bump version: v2.2.0 → v2.2.1