Bumping version to 1.9.0 and generate changelog

Bumping version to 1.9.0rc1 and generate changelog

Bumping version to 1.9.0b2 and generate changelog

Bumping version to 1.9.0b1 and generate changelog

Bumping version to 1.8.1 and generate changelog

Bumping version to 1.8.0 and generate changelog

Bumping version to 1.8.0rc1 and generate changelog

Bumping version to 1.8.0b3 and generate changelog

Bumping version to 1.7.7 and generate changelog

Bumping version to 1.7.6 and generate changelog