Rented Devices View should show Expiration Date

[christroutner]

The scope of this issue is to create a PR for adding the expiration date to the rendedDeviceItem component in the Rented Devices view. The feature has these parts:

1. The expiration date is stored in the public device model. This information is automatically retrieved from the server and populated into the Vuex store in the state.ownedDevices object when the user logs in. That information is for devices owned by the user. The logic for that feature can be copied to retrieve data on devices rented by user.

2. The expiration date should be displayed prominently, in the location indicated by the screenshot below. It would be nice if the expiration date changed color, based on the amount of time till the expiration date is reached. An idea: red for less than 24 hours, orange for less than 4 days, and green for anything greater than 4 days.

[christroutner]

[christroutner]

Instructions for interacting with the Rented Devices view can be found in the July 2018 video:
https://p2pvps.org/july-2018-project-update/