Add descriptive debug logs

[aroticoz]

When encountering error relating to a missing key/value in Consul, pandora does not always give a descriptive error message.

It would be great to have custom debug logs which are able to output detailed information about all the working pieces:

• application name
• pandora cluster
• consul address
• machine name
• key we're trying to get

An odd cause I encountered is pandora reporting a missing key, where actually the whole folder was missing, due to a wrongly configured application name.

Let me know if you need more information