puppet: trivial linting cases

http://puppet-lint.com/ gives you hint about your puppet manifests. This
patch:
* favorize single quoted strings
* escape variables using '${}' construct
* clean out a few whitespaces
* align arrows, see the style guide at:
 http://docs.puppetlabs.com/guides/style_guide.html#arrow-alignment
* 'ensure' statement should be the first one in a resource
puppet: set vim modeline

The puppet manifest is indented using four spaces. Set a vim modeline
accordingly.
puppet: compress resources

Each resource should be in its own resource block. That makes potential
puppet stack trace unambiguous.

http://docs.puppetlabs.com/guides/style_guide.html#compression
puppet: get rid of trailing semicolon

Older puppet versions needed trailing semicolons to terminate the
resources parameters.  It should no more be needed nowadays so replace
them with comma.  This way, whenever someone add a new line, it is not
needed to update the previous line as well.