Switch to openapi-generator

Current issues: I have to disable the spec check for the generator to start. The spec seems to contain some issues.
Then, I get the following errors:
oapi-1      | FAIL  [github.com/nautobot/go-nautobot](http://github.com/nautobot/go-nautobot) [build failed]
oapi-1      | # [github.com/nautobot/go-nautobot](http://github.com/nautobot/go-nautobot) [[github.com/nautobot/go-nautobot.test](http://github.com/nautobot/go-nautobot.test)]
oapi-1      | ./model_bulk_writable_device_type_request.go:26:21: syntax error: unexpected * in struct type; possibly missing semicolon or newline or }
oapi-1      | ./model_bulk_writable_device_type_request.go:37:8: syntax error: unexpected ] after top level declaration
oapi-1      | ./model_patched_bulk_writable_device_type_request.go:26:21: syntax error: unexpected * in struct type; possibly missing semicolon or newline or }
oapi-1      | ./model_patched_bulk_writable_device_type_request.go:37:8: syntax error: unexpected ] after top level declaration
oapi-1      | ./model_patched_writable_device_type_request.go:23:21: syntax error: unexpected * in struct type; possibly missing semicolon or newline or }
oapi-1      | ./model_patched_writable_device_type_request.go:35:8: syntax error: unexpected ] after top level declaration
oapi-1      | ./model_power_feed.go:75:28: syntax error: unexpected {, expected expression
oapi-1      | ./model_power_feed.go:76:2: syntax error: non-declaration statement outside function body
oapi-1      | ./model_power_feed.go:77:31: syntax error: unexpected {, expected expression
oapi-1      | ./model_power_feed.go:79:29: syntax error: unexpected {, expected expression
oapi-1      | ./model_power_feed.go:96:28: syntax error: unexpected {, expected expression
oapi-1      | ./model_power_feed.go:97:2: syntax error: non-declaration statement outside function body
oapi-1      | ./model_power_feed.go:98:31: syntax error: unexpected {, expected expression
oapi-1      | ./model_power_feed.go:100:29: syntax error: unexpected {, expected expression
oapi-1      | ./model_prefix.go:72:25: syntax error: unexpected {, expected expression
oapi-1      | ./model_prefix.go:73:2: syntax error: non-declaration statement outside function body
oapi-1      | ./model_prefix.go:91:25: syntax error: unexpected {, expected expression
oapi-1      | ./model_prefix.go:92:2: syntax error: non-declaration statement outside function body
oapi-1      | ./model_writable_device_type_request.go:24:21: syntax error: unexpected * in struct type; possibly missing semicolon or newline or }
oapi-1      | ./model_writable_device_type_request.go:36:8: syntax error: unexpected ] after top level declaration
oapi-1 exited with code 1
nautobot / go-nautobot

Switch to openapi-generator #28
