Using unknown parameter resolver results in unhelpful error text

[viraptor]

With parameters file:

foo_param:
  stack: some_stack/output

Executing diff on market-csp-collector in us-east-1
error: stack. Use --trace to view backtrace

With stack trace:

/opt/boxen/rbenv/versions/2.3.6/lib/ruby/gems/2.3.0/gems/stack_master-1.8.0/lib/stack_master/parameter_resolver.rb:34:in `rescue in require_parameter_resolver': stack (StackMaster::ParameterResolver::ResolverNotFound)
	from /opt/boxen/rbenv/versions/2.3.6/lib/ruby/gems/2.3.0/gems/stack_master-1.8.0/lib/stack_master/parameter_resolver.rb:30:in `require_parameter_resolver'
	from /opt/boxen/rbenv/versions/2.3.6/lib/ruby/gems/2.3.0/gems/stack_master-1.8.0/lib/stack_master/parameter_resolver.rb:45:in `rescue in load_parameter_resolver'
	from /opt/boxen/rbenv/versions/2.3.6/lib/ruby/gems/2.3.0/gems/stack_master-1.8.0/lib/stack_master/parameter_resolver.rb:40:in `load_parameter_resolver'

Better error would be:

parameter resolver ${foo} not found (requested in parameters/foo.yml)