Operations: callback not always called

[pilhuhn]

Suppose I pass in an incorrect parameter hash for invoke_generic_operation, the callback is not called, but the method bails out with a 'fail':

RuntimeError: Hash property resourcePath must be specified
./lib/hawkular/operations/operations_api.rb:216:in `block in check_pre_conditions'
./lib/hawkular/operations/operations_api.rb:215:in `each'
./lib/hawkular/operations/operations_api.rb:215:in `check_pre_conditions'
./lib/hawkular/operations/operations_api.rb:105:in `invoke_generic_operation'
./spec/integration/operations_spec.rb:78:in `block (2 levels) in <module:RSpec>'

I think the user would only expect this if no callback is defined at all.