extend weave::install to support ensure => latest,

[hesco]

class weave::install (
  $ensure = $weave::params::ensure,

should support ensure => latest, but requires semantic versioning in upstream zettio/weave project to avoid backflips required to sort out which git version hash might be the latest.

See:
resolve #110, provide for semantic versioning
semantic versioning #110

[hesco]

ramindk | hesco: Don't imagine it would be hard to write a function that executes on the master and writes message out. I'd keep it out of the catalog. However lots of users do not like random things complain to their logs.

hesco | ramindk: I can see a switch to enable/disable that updates_available message. The upstream project is moving pretty fast right now, and for my own self, I'd love help watching out for when I need to upgrade. Still harping on the upstream team to expose semantic versioning, rather than their silly git ref hashes.

hesco | as I imagine it, this Notify[] would run ONLY on the docker hosts, though. No where else.