Test fixtures fail validation with gbfs-json-schema v4.4.0

[jcpitre]

In MobilityData/gbfs-json-schema#208 we made some changes to the schemas and published a new schema release v4.4.0

Trying to include this release in gbfs-validator-java produced some errors in the tests:

testSuccessfulV2_0Validation     expected: <0> but was: <6>
testSuccessfulV2_1Validation     expected: <0> but was: <6>
testSuccessfulV2_2Validation     expected: <0> but was: <6>
testSuccessfulV2_3Validation     expected: <0> but was: <6>
testSuccessfulV3_0Validation     expected: <0> but was: <3>
testSuccessfulV3_1RC3Validation  expected: <0> but was: <3>
testMissingRequiredFile          expected: <1> but was: <7>
testMissingNotRequiredFile       expected: <0> but was: <6>

Cause: MobilityData/gbfs-json-schema#208 requires a feed to declare at least one of station_status / vehicle_status (free_bike_status in v2.x), and requires station_status whenever station_information is declared. The fixture gbfs.json files declare only system_information and station_information, so they are now invalid — 6 errors in v2.x (the violations are counted once per language block) and 3 in v3.x.