Get defined schemas as python dictionaries

[roo-oliv]

Despite Flasgger gathers up all defined schemas it does not exposes an interfacing method to enable querying them. This PR adds this missing interfacing method: Swagger::get_schema(schema_id)

This may be useful when an application needs to access the schema for further validation steps, such as dropping additional parameters in a request body.

[coveralls]

Coverage increased (+0.03%) to 93.038% when pulling b235e98 on allrod5:get-schema into 8944594 on rochacbruno:master.

[coveralls]

Coverage increased (+0.03%) to 93.038% when pulling 117f043 on allrod5:get-schema into 8944594 on rochacbruno:master.

[coveralls]

Coverage increased (+0.03%) to 93.038% when pulling 6704072 on allrod5:get-schema into 8944594 on rochacbruno:master.