GH-186 Downgrade specification to 3.0.3 (Fix #186)

Author: dzikoysk

openapi-annotation-processor/src/main/kotlin/io/javalin/openapi/processor/generators/OpenApiGenerator.kt

@@ -98,7 +98,7 @@ internal class OpenApiGenerator {
      */
     private fun generateSchema(openApiAnnotations: Collection<Pair<Element, OpenApi>>): String {
         val openApi = JsonObject()
-        openApi.addProperty("openapi", "3.1.0")
+        openApi.addProperty("openapi", "3.0.3")
 
         // fill info
         val info = JsonObject()

openapi-annotation-processor/src/test/kotlin/io/javalin/openapi/processor/OpenApiAnnotationTest.kt

@@ -23,7 +23,7 @@ internal class OpenApiAnnotationTest : OpenApiAnnotationProcessorSpecification()
     fun should_generate_info() = withOpenApi("should_generate_info") {
         assertThatJson(it)
             .isObject
-            .containsEntry("openapi", "3.1.0")
+            .containsEntry("openapi", "3.0.3")
             .containsEntry("info", json("""{ "title":"", "version": "" }"""))
     }