Bump version to 6.9.15

Bump version

Merge pull request AugurProject#3146 from AugurProject/6.9.13

6.9.13

6.9.12

Merge pull request AugurProject#3143 from AugurProject/6.9.11

6.9.11

Merge pull request AugurProject#3142 from AugurProject/6.9.10

6.9.10

Merge pull request AugurProject#3140 from AugurProject/6.9.9

6.9.9

6.9.8 (AugurProject#3137)

bup version to 6.9.7 (AugurProject#3134)

6.9.6 (AugurProject#3132)