CBLT-254:  use curl instead of maven to upload artifacts

Change-Id: I69a4312e7a94cadeb68c8d6fac8c3ac7614b5363
Reviewed-on: http://review.couchbase.org/35554
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>