Add special BAMBOO_TCP_PORT variable logic to add tcp mode service

Defining BAMBOO_TCP_PORT in the Marathon task definition, e.g.

	{
	  "id": "test",
	  "cmd": "python -m SimpleHTTPServer $PORT0",
	  "cpus": 0.1,
	  "mem": 90,
	  "ports": [0],
	  "instances": 1
	  "env": {
	    "BAMBOO_TCP_PORT": "1080"
	  }
	}

leads to

	listen ::test-cluster-tcp :1081
	        mode tcp
	        option tcplog
	        balance roundrobin

        	server ::test-192.168.2.2-31001 192.168.2.2:31001

in the haproxy configuration.

Fixes QubitProducts#28.

config/haproxy_template.cfg

@@ -25,11 +25,6 @@ defaults
         timeout client  50000
         timeout server  50000
 
-        stats enable
-        # CHANGE: Your stats credentials
-        stats auth admin:admin
-        stats uri /haproxy_stats
-
         errorfile 400 /etc/haproxy/errors/400.http
         errorfile 403 /etc/haproxy/errors/403.http
         errorfile 408 /etc/haproxy/errors/408.http
@@ -53,9 +48,20 @@ frontend http-in
         use_backend {{ $app.EscapedId }}-cluster if {{ $app.EscapedId }}-aclrule
         {{ end }} {{ end }}
 
-{{ range $index, $app := .Apps }}
-backend {{ $app.EscapedId }}-cluster
-        {{ if $app.HealthCheckPath }}
+        stats enable
+        # CHANGE: Your stats credentials
+        stats auth admin:admin
+        stats uri /haproxy_stats
+
+{{ range $index, $app := .Apps }} {{ if $app.Env.BAMBOO_TCP_PORT }}
+listen {{ $app.EscapedId }}-cluster-tcp :{{ $app.Env.BAMBOO_TCP_PORT }}
+        mode tcp
+        option tcplog
+        balance roundrobin
+        {{ range $page, $task := .Tasks }}
+        server {{ $app.EscapedId}}-{{ $task.Host }}-{{ $task.Port }} {{ $task.Host }}:{{ $task.Port }} {{ if $app.HealthCheckPath }} check inter 30000 {{ end }} {{ end }}
+{{ end }}
+backend {{ $app.EscapedId }}-cluster{{ if $app.HealthCheckPath }}
         option httpchk GET {{ $app.HealthCheckPath }}
         {{ end }}
         balance leastconn