Docker image的推進

仔細的看一下tag之前與之後的image list變化，不難發現他會多個的image，這個是代表我們把某個image的tag換給新的image使用了，因此，原本tag的imager就會使用來當tag。(另外，latest是預設最新的tag，也不能隨便拿來用唷。)

 2016-03-26 13:53:53 ☆  raspberrypi in ~/project/images/rpi-node
± |master ✓| → docker images
REPOSITORY                   TAG                 IMAGE ID            CREATED             SIZE
linkerlab/rpi-node           5.9.1-armv7l        dc357709a71c        11 minutes ago      115 MB
test                         latest              c08ac6eb0662        About an hour ago   80.04 MB
linkerlab/rpi-node           latest              715750aaa12d        2 hours ago         115 MB
resin/rpi-raspbian           latest              85c88f0c30bf        3 days ago          80.04 MB
hypriot/rpi-node             latest              286e53bda778        8 days ago          435.9 MB
hypriot/rpi-alpine-scratch   latest              f87d69083db4        4 weeks ago         4.976 MB

 2016-03-26 13:54:00 ☆  raspberrypi in ~/project/images/rpi-node
± |master ✓| → docker tag linkerlab/rpi-node:5.9.1-armv7l linkerlab/rpi-node:latest

 2016-03-26 13:54:52 ☆  raspberrypi in ~/project/images/rpi-node
± |master ✓| → docker images
REPOSITORY                   TAG                 IMAGE ID            CREATED             SIZE
linkerlab/rpi-node           5.9.1-armv7l        dc357709a71c        12 minutes ago      115 MB
linkerlab/rpi-node           latest              dc357709a71c        12 minutes ago      115 MB
test                         latest              c08ac6eb0662        About an hour ago   80.04 MB
<none>                       <none>              715750aaa12d        2 hours ago         115 MB
resin/rpi-raspbian           latest              85c88f0c30bf        3 days ago          80.04 MB
hypriot/rpi-node             latest              286e53bda778        8 days ago          435.9 MB
hypriot/rpi-alpine-scratch   latest              f87d69083db4        4 weeks ago         4.976 MB