Inverted some logic, so we don't need slow checks

Instead just use method lookup, with defaults
Specified how command/query/interactor should behave
fixed typo
Inverted logic (don't authorise by default)

Way better according to open/closed principle
Implemented raising an error when not implemented by not implementing

We do this for execute as well, so I don't see why we should handle this differently
Simplified and optimised missing values check
fixed test descriptions
Merge pull request #55 from Factlink/removed-respond-to-checks

Removed respond to checks