Kelvin/install from package

Two changes:
* Install couchbase from package without curl:
This allows the installation of couchbase without having to download
couchbase on every node. This change is intended for users that have an
internal repository serving up their .deb files
* Change curl download location from /tmp to /opt:
This is because the /tmp directory gets wiped on every reboot, when a
couchbase node is rebooted the first time puppet runs it will download
the package again. Not ideal.