Merge pull request bannzai#139 from kishikawakatsumi/release_084

Bump version to 0.8.4

Merge pull request bannzai#132 from kishikawakatsumi/release-083

Bump version to 0.8.3

Merge pull request bannzai#128 from kishikawakatsumi/release082

Bump version to 0.8.2

Merge pull request bannzai#122 from kishikawakatsumi/release081

Bump version to 0.8.1

Merge pull request bannzai#107 from kishikawakatsumi/release080

Bump version to 0.8.0

Merge pull request bannzai#100 from kishikawakatsumi/release_073

Bump version to 0.7.3

Merge pull request bannzai#78 from kishikawakatsumi/release-072

Bump version to 0.7.2

Merge pull request bannzai#72 from kishikawakatsumi/release-071

Bump version to 0.7.1

Merge pull request bannzai#65 from kishikawakatsumi/release_070

Bump version to 0.7.0

Merge pull request bannzai#56 from kishikawakatsumi/release_064

Bump version to 0.6.4