Set ensurable feature, returning installed version on self.instances
BUGFIX : let the :ensure value returned by parse_pkgin_line
Remove mangling of ensure property, now set to installed version
Return current version for latest if no candidate is available
Fix version number in output from instances
Fix results for tests on latest method
Handle install of files to fixed version
BUGFIX : protect against empty arrays
Add some tests for fixed version installs
Capture error on unittests
BUGFIX : return ensure to get version number
BUGFIX : pass the :ensure value given by parsing line
Merge pull request #12 from Telefonica/task/versionable

Task/versionable