How to: Consul Catalog provider
Use: `reproxy --consul-catalog.enabled`

Consul Catalog provider calls Consul API periodically (every second by default) to obtain services, which has any tag with `reproxy.` prefix. User can redefine check interval with `--consul-catalog.interval` command line flag as well as consul address with `--consul-catalog.address` command line option. The default address is `http://127.0.0.1:8500`. 

For example:
```
reproxy --consul-catalog.enabled --consul-catalog.address=http://192.168.1.100:8500 --consul-catalog.interval=10s  
```

By default, provider sets values for every service:
- enabled `false`
- server `*`
- route `^/(.*)`
- dest `http://
/$1`
- ping `http://
/ping`

This default can be changed with tags:

- `reproxy.server` - server (hostname) to match. Also, can be a list of comma-separated servers.
- `reproxy.route` - source route (location)
- `reproxy.dest` - destination path. Note: this is not full url, but just the path which will be appended to service's ip:port
- `reproxy.port` - destination port for the discovered service
- `reproxy.remote` - restrict access to the route with a list of comma-separated subnets or ips
- `reproxy.auth` - require basic auth for the route with comma-separated `user:bcrypt_hash` pairs (generated by `htpasswd -nbB`)
- `reproxy.ping` - ping path for the destination service.
- `reproxy.enabled` - enable (`yes`, `true`, `1`) or disable (`any different value`) service from reproxy destinations.