Validate that Configuration Exists during Config Load

[eak13]

Problem description
Invalid variable configuration can cause null pointer issues leading to runtime errors (e.g. uninitialized maps). When configuration is loaded specific sub-command validations are not performed until the sub-command operation. There is a need to validate that configuration exists at the time it is loaded.
Reference issue #190 - Invalid config could cause runtime error

Proposed change
Enhance the airship config load to throw a warning if there is no configuration.

Potential impacts
By expanding the pool of upfront validations, we can eliminate runtime errors due to bad configurations at the sub-command level.

[ian-howell]

I believe this may be implemented already, but I'll take a look prior to closing

[ian-howell]

Closing as this is a duplicate of #190