Adds healthCheckCriticalTimeout to discovery props

The healthCheckCriticalTimeout property tells consul to deregister services in critical longer than timeout.

Fixes gh-210

src/main/bash/travis_install_consul.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-CONSUL_VER="0.6.3"
+CONSUL_VER="0.7.2"
 CONSUL_ZIP="consul_${CONSUL_VER}_linux_amd64.zip"
 IGNORE_CERTS="${IGNORE_CERTS:-no}"