Fix coverage epsilon.

BUILD SUCCESSFUL

Reviewed at https://reviews.apache.org/r/27935/
Remove non-fixed tickets from CHANGELOG.

Bugs closed: AURORA-711

Reviewed at https://reviews.apache.org/r/27934/
Fix review bot to use correct latest diff time.

Reviewed at https://reviews.apache.org/r/27941/
Store host attributes alongside offers to reduce number of lookups.

Bugs closed: AURORA-913

Reviewed at https://reviews.apache.org/r/27902/