Add Healthcheck route

This is a route that connects to the database, connects to ldap, pings the proxmox api, and returns a json blob stating whether or not it can connect.

This should allow us to more reasonably monitor on whether or not proxtstar is in working order. The route should not be behind auth so datadog can hit it

How I want this to work
```
GET /api/v1/healthcheck
```
That would return 200 only when both ldap and the database connect correctly, and a 5XX range response when they don't. Different 5XX code for ldap down, sql down and both down. Return the json no matter what the status code is.
```json
{
"ldap": {
"status": true,
"server": "stone.csh.rit.edu"
},
"database": {
"status": true,
"server": "mysql.csh.rit.edu"
},
"proxmox": {
"status": true
},
}
```