Add a :headers option to invite
Omit the extra newline if there are no headers passed to #invite
Move headers to the end of the SIP INVITE
Remove debugging #p call from scenario_spec
Scenario validation with structured error messages.
Merge pull request #35 from mojolingo/feature/validation

Feature/validation
Remove some unused requires
Avoid referring to manifests by their format (YAML), but instead by their scemantic meaning
Fix some documentation
Add documentation for basic Scenario initialization
Remove some methods from the Scenario public API
Add markers for better test coverage
Reduce spec duplication
Simple sting quoting
Remove unsafe symbolisation of untrusted input
Use safer heredocs
Switch incorrect logging
Ditch 'should' from test descriptions
This simple test shouldn't care about invites
Flesh out invite specs