Add script that checks installed plugin version
Remove old plugin file and directory before installing new plugin version
Fix delete bug
Add check for presence of plugin manifest
Merge branch 'master' into plugin-versions
Use new facter-based method of detecting installed plugin versions based on approach suggested by jlambert121
Remove unused script
Remove unused variable
Update test cases
Merge pull request #53 from jchristi/plugin-versions

Allow specific versions of jenkins plugins to be installed