Change minion to node

Contination of #1111

I tried to keep this PR down to just a simple search-n-replace to keep
things simple.  I may have gone too far in some spots but its easy to
roll those back if needed.

I avoided renaming `contrib/mesos/pkg/minion` because there's already
a `contrib/mesos/pkg/node` dir and fixing that will require a bit of work
due to a circular import chain that pops up. So I'm saving that for a
follow-on PR.

I rolled back some of this from a previous commit because it just got
to big/messy. Will follow up with additional PRs

Signed-off-by: Doug Davis <dug@us.ibm.com>

api/swagger-spec/v1.json

@@ -16760,7 +16760,7 @@
    },
    "v1.Node": {
     "id": "v1.Node",
-    "description": "Node is a worker node in Kubernetes, formerly known as minion. Each node will have a unique identifier in the cache (i.e. in etcd).",
+    "description": "Node is a worker node in Kubernetes. Each node will have a unique identifier in the cache (i.e. in etcd).",
     "properties": {
      "kind": {
       "type": "string",