Add a publish action to items to allow them to post data to a remote site

[RobNicholsGDS]

Note that it is possible to post from the new items publish view to the esdas controller. However, if you try doing that in development with only one instance of the app running, the connection will time out because the app is unable to handle the new HTTP request while it is still trying to process the current one.

I was able to test the set up locally by running two instances of the app. To do this I opened two consoles and entered each with one of these two commands:

• Client: PUBLISH_URL=http://localhost:3001/esdas.json rails s
• API endpoint: rails s -p 3001 -P 333