Update to pallet 0.8.0-RC.7
Improve maintenance of replica set members

When nodes are added or removed, this should be reflected in the replica
set configuration.
Add support for mongo MMS agent install
Updated metadata for 0.8.0-alpha.2
Updated project.clj, release notes and readme for 0.8.0-alpha.2
Merge branch 'release/0.8.0-alpha.2' into develop