Support RAML schemas without JSON schema

[danascheider]

Summary

In addition to JSON Schema, RAML provides the option of native RAML schemas and examples. Rambo should be able to generate examples - and Rambo-generated tests should be able to validate responses - written in native RAML instead of JSON Schema.

Expected Behavior

Rambo should generate tests, complete with appropriate examples and schema validation, off of RAML docs whether they use JSON Schema or RAML schemas/examples.

Current Behavior

Currently, all examples have to be written in JSON, and all schemas in JSON Schema, in order for Rambo and the tests it generates to work.

Possible Solution

Rambo could convert RAML schema to JSON schema, or may be able to do something simpler using the capabilities of the raml-rb gem. Will have to look into this further.

Context

In order to be most useful to Rambo's users, it should be flexible in what it requires of RAML files, accepting any RAML file and generating the appropriate tests. See also #57 . I am labeling this issue medium priority since it does not affect Repaymnt Estimatr or Mandolin.