Examples as interactive acceptance tests

[skipor]

API and config are evolving, and example configs are not verified to be OK.
Also, it would be great to a user have the ability to run any example.

Proposal: example directory with subdirectories.
In any subdirectory, there is config example, and test file, that runs Pandora with this config and verifies, that all is ok. Also, there can be ammo file, custom pandora main.go.

Any example should show some part of Pandora features, so the user just could copy paste parts from different examples to create its own start config.

This should be somewhat interactive and human readable #35 acceptance tests