Unify stateful and stateless log collection

There should be support through cbopinfo to copy logs from cb pods directly.

Currently collectinfo flag collects the logs and be stores it in pod itself. Later we can copy the logs using "kubectl cp" command.

In field scenario, we can have many pods, which will be difficult for us to copy the logs from each pod. So it will be good if this can be done as part of our tool and get the logs as single tar-ball.

]$ ./build/bin/cbopinfo -kubeconfig ~/.kube/config -namespace ashwin -collectinfo
Server logs accessible via: kubectl cp ashwin/test-couchbase-dt7pw-0002:/tmp/cbinfo-ashwin-test-couchbase-dt7pw-0002-20180719T173639+0530.zip .
Server logs accessible via: kubectl cp ashwin/test-couchbase-dt7pw-0001:/tmp/cbinfo-ashwin-test-couchbase-dt7pw-0001-20180719T173639+0530.zip .
Server logs accessible via: kubectl cp ashwin/test-couchbase-dt7pw-0000:/tmp/cbinfo-ashwin-test-couchbase-dt7pw-0000-20180719T173639+0530.zip .
Wrote cluster information to cbopinfo-20180719T173639+0530.tar.gz
Ashwins-MacBook-Pro:couchbase-operator]${noformat}