api: use schemathesis to test API using openAPI spec

[matthiasschaub]

https://github.com/schemathesis/schemathesis

[matthiasschaub]

st run --checks all https://api.quality.ohsome.org/v1/openapi.json

Schema location: https://api.quality.ohsome.org/v1/openapi.json
Base URL: https://api.quality.ohsome.org/v1
Specification version: Open API 3.1.0
Workers: 1
Collected API operations: 10

POST /v1/indicators/{key} F
GET /v1/metadata .
GET /v1/metadata/topics .
GET /v1/metadata/topics/{key} .
GET /v1/metadata/quality-dimensions .
GET /v1/metadata/quality-dimensions/{key} .
GET /v1/metadata/projects .
GET /v1/metadata/projects/{key} F
GET /v1/metadata/indicators .
GET /v1/metadata/indicators/{key} .

===== SUMMARY =====

Performed checks:
    not_a_server_error                              687 / 797 passed          FAILED
    status_code_conformance                         687 / 797 passed          FAILED
    content_type_conformance                        797 / 797 passed          PASSED
    response_headers_conformance                    797 / 797 passed          PASSED
    response_schema_conformance                     348 / 797 passed          FAILED

Hint: You can visualize test results in Schemathesis.io by using `--report` in your CLI command.

===== 8 passed, 2 failed in 82.58s =====

[matthiasschaub]

Retry after #704 has been merged.