Handle ping/1 function failure condition

[holsee]

DMS.ping/1 has a contract of returning :ping on the successful acknowledgement that service will return true when asked if alive for timeout period.

It also states it will return :pang when this is not the case when the DMS will not guarantee to signal alive to be true for the service. This condition is not implemented.

[holsee]

We need to handle the other returned options from starting the service process