Refactor `get(/apps/:appName)` with a more precise health check

[MFatigati]

Two options:

1. change docker-compose templates to use health checks, and then update the route to consider that data (example syntax. But that data may only be exposed on containers, and thus be less relevant, or inaccessible, for this particular route. Possibly available through the API via get /tasks

"Status": {
"Timestamp": "2016-06-07T21:07:31.290032978Z",
"State": "running",
"Message": "started",
"ContainerStatus": {
"ContainerID": "e5d62702a1b48d01c3e02ca1e0212a250801fa8d67caca0b6f35919ebc12f035",
"PID": 677
}

2. Manually implement some more rigorous logic. Such as, if there is a more recent task that is running for more than 1 minute, don’t consider it problematic.