Problem with envconsul timeouts due to consul long-polling

[tomasfse]

Hello,

I've sent a pull request to solve a problem with envconsul.

#200

Consul uses long-polling to allow envconsul "subscribe" to config changes, and due to nginx is used as reverse proxy the connection is being dropped by nginx continuously. Consul have a default wait time for 5 minutes.

I've increased to 10 minutes the nginx timeout for location "/" and the problem is solved.