Merge pull request #11 from xeon22/develop

- Added versions and checksums for latest versions
Backfill Stash 2.8.0 checksum
Add Stash backup client 1.0.0 checksum
Default to Stash 2.8.1, Stash Backup Client 1.0.0
Remove test directory from chefignore (Test Kitchen fix -- see RiotGames/berkshelf#587 and RiotGames/ridley#192)
- Added extra settings for plugin in the stash-config.properties file