Upgrade to alpine 3.6

(cherry picked from commit 0aae2ef)

Author: Andrew Kerr

contrib/docker/plugin/Dockerfile

@@ -1,4 +1,7 @@
-FROM alpine:3.5
+FROM alpine:3.6
+
+# Use APK mirrors for fault tolerance
+RUN printf "http://dl-1.alpinelinux.org/alpine/v3.6/main\nhttp://dl-2.alpinelinux.org/alpine/v3.6/main\nhttp://dl-3.alpinelinux.org/alpine/v3.6/main\nhttp://dl-4.alpinelinux.org/alpine/v3.6/main\nhttp://dl-5.alpinelinux.org/alpine/v3.6/main\n\nhttp://dl-1.alpinelinux.org/alpine/v3.6/community\nhttp://dl-2.alpinelinux.org/alpine/v3.6/community\nhttp://dl-3.alpinelinux.org/alpine/v3.6/community\nhttp://dl-4.alpinelinux.org/alpine/v3.6/community\nhttp://dl-5.alpinelinux.org/alpine/v3.6/community" > /etc/apk/repositories
 
 RUN apk update && \
     apk add coreutils nfs-utils util-linux blkid multipath-tools lsscsi e2fsprogs xfsprogs bash

contrib/rancher/Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3.4
+FROM alpine:3.6
 
 RUN mkdir /lib64 && ln -s /lib/libc.musl-x86_64.so.1 /lib64/ld-linux-x86-64.so.2
 RUN mkdir -p /netapp /etc/netappdvp
@@ -20,6 +20,9 @@ RUN ln -s /host/var/log /var/log
 RUN mkdir -p /host/var/lib/docker-volumes
 RUN ln -s /host/var/lib/docker-volumes /var/lib/docker-volumes
 
+# Use APK mirrors for fault tolerance
+RUN printf "http://dl-1.alpinelinux.org/alpine/v3.6/main\nhttp://dl-2.alpinelinux.org/alpine/v3.6/main\nhttp://dl-3.alpinelinux.org/alpine/v3.6/main\nhttp://dl-4.alpinelinux.org/alpine/v3.6/main\nhttp://dl-5.alpinelinux.org/alpine/v3.6/main\n\nhttp://dl-1.alpinelinux.org/alpine/v3.6/community\nhttp://dl-2.alpinelinux.org/alpine/v3.6/community\nhttp://dl-3.alpinelinux.org/alpine/v3.6/community\nhttp://dl-4.alpinelinux.org/alpine/v3.6/community\nhttp://dl-5.alpinelinux.org/alpine/v3.6/community" > /etc/apk/repositories
+
 RUN apk update && apk add curl vim screen tmux bash jq
 
 #ADD netappdvp-1.3.tar.gz /netapp