Merge pull request #3259 from gaurav-nelson/RouterVariablesFor3.4

Added Rotuter Variables for version 3.4

Author: Gaurav Nelson

architecture/core_concepts/routes.adoc

@@ -201,10 +201,12 @@ variables on the *deployment config* for the router to alter its configuration.
 |`*PROJECT_LABELS*` |  | A label selector to apply to projects to watch, emtpy means all.
 |`*RELOAD_SCRIPT*` |  | The path to the reload script to use to reload the router.
 |`*ROUTER_BACKEND_CHECK_INTERVAL*` | 5000ms | Length of time between subsequent "liveness" checks on backends.
+|`*ROUTER_COMPRESSION_MIME*` | "text/html text/plain text/css" | A space separated list of mime types to compress.
 |`*ROUTER_DEFAULT_CLIENT_TIMEOUT*`| 30s | Length of time within which a client has to acknowledge or send data.
 |`*ROUTER_DEFAULT_CONNECT_TIMEOUT*`| 5s | The maximum connect time.
 |`*ROUTER_DEFAULT_SERVER_TIMEOUT*`| 30s | Length of time within which a server has to acknowledge or send data.
 |`*ROUTER_DEFAULT_TUNNEL_TIMEOUT*` | 1h | Length of time till which TCP or WebSocket connections will remain open.
+|`*ROUTER_ENABLE_COMPRESSION*`| false | If `true`, compress responses when possible.
 |`*ROUTER_LOG_LEVEL*` | warning | The log level to send to the syslog server.
 |`*ROUTER_OVERRIDE_HOSTNAME*`|  | If set, override the spec.host value for a route with the template in ROUTER_SUBDOMAIN.
 |`*ROUTER_SERVICE_HTTPS_PORT*` | 443 | Port to listen for https requests.