Include the settings for nats ping timeouts

This microbosh manifest didn't include the settings for ping_max_outstanding and ping_interval, which users will probably need to change based on https://groups.google.com/a/cloudfoundry.org/forum/#!topic/bosh-users/mWo7A-HqJoo
Merge pull request #22 from programsam/master

Include the settings for nats ping timeouts