fix(router): add check command for nginx config

Check for `<no value>` in nginx config, which usually means that
something is wrong with the configuration in etcd.

Author: Sam Dodrill

router/bin/check

@@ -0,0 +1,12 @@
+#!/bin/bash
+#
+# Check that the configuration for deis-router is valid.
+#
+
+if grep -q "<no value>" $1 ; then
+	exit 1
+fi
+
+if ! /usr/sbin/nginx -t -c $1 ; then
+	exit 1
+fi

router/conf.d/nginx.conf.toml

@@ -11,5 +11,5 @@ keys = [
   "/deis/controller",
   "/deis/builder",
 ]
-check_cmd  = "/usr/sbin/nginx -t -c {{ .src }}"
+check_cmd  = "/app/bin/check {{ .src }}"
 reload_cmd = "/usr/sbin/nginx -s reload"