Initialize swagger checker from swagger object directly

[ben-axnick]

Intended to address: https://github.com/westfieldlabs/apivore/issues/100

Background

Currently the SwaggerChecker initialize method has no flexibility about how Apivore::Swagger is constructed. By accepting a full object, the client gains the flexibility to fetch a swagger file however it wishes to, whether by file, remote HTTPS, or carrier pigeon.

Since README and specs revolve around .instance_for, whose signature remains unchanged, there are no other changes required.

What have I done?

• The previous initialization routine has been moved to .from_local_route, and .instance_for has been updated to reflect that.
• The new initializer accepts a Apivore::Swagger (or any object that accepts #validate and #each_response)

[ben-axnick]

Closing because I don't want to see this in my PR list forever.

If you're interested in merging down the line, I'm happy to help make any changes you feel need to be made.

[philsturgeon]

Wish I saw this before making #118. If there is interest from the maintainers about that PR I'll pull this in and tweak it a little. I'm unhappy with the two-different places to check if JSON/YAML.

[ben-axnick]

Yeah, I had closed owing to the fact that it seemed like PRs weren't being handled or looked into at all by the maintainers, hopefully your PR meets with greater success.

[philsturgeon]

Thank you, but I just leave mine floating around like dingleberries!