Make an index page for the Adam server

[mydatascience]

When I go to the page I'd like to see at least something like:

Hello. Welcome to ADAM. Here are the Endpoints:

The following are the admin endpoints:

GET /onboard - list all onboard certificates
GET /onboard/{cn} - get a specific onboard certificate
POST /onboard - upload a new onboarding certificate
DELETE /onboard - clear all onboarding certificates
DELETE /onboard/{cn} - delete a specific onboarding certificate
GET /device - list all devices
GET /device/{uuid} - get details of one device
GET /device/{uuid}/config - get config for one device
PUT /device/{uuid}/config - update config for one device
GET /device/{uuid}/logs - get all known logs for one device; set header X-Stream=true to stream all new logs instead
GET /device/{uuid}/info - get all known info messages for one device; set header X-Stream=true to stream all new info instead
POST /device - create a new device
DELETE /device - delete all devices
DELETE /device/{uuid} - delete one specific device

Even better if I see that I have some EVE connected to ADAM

[rvs]

Yeah, that's been on @deitch and my TODO list for some time (and I suppose it is also related to #28 since you can serve that one up as well)

That said, we still not quite out of the weeds on basic functionality -- patches are VERY welcome, of course.