deal with params without default values

[DimaPoliuha]

Params without a default value, or examples

Descriptions
Almost all API specs have a lot of params without default values (required and not required).

Solution
It would be great to create the file with helper functions (or classes) that will help to generate those values (for example function, that returns random int) and attach that file to the generated locustio file.

Problems
There can also be params without param_type specified so we need to consider how we'll deal with those situations.

Alternatives
The straightforward solution is to generate an additional file that will contain all params without values so people need to add values themself.