test(tutorials): log validation errors in SoapArrayToJsonTutorialTest

- Added `.log().ifValidationFails()` to improve debugging of failing test scenarios.

Author: predic8

distribution/src/test/java/com/predic8/membrane/tutorials/transformation/SoapArrayToJsonTutorialTest.java

@@ -37,6 +37,7 @@ void soapArrayIsConvertedToJsonArray() throws IOException {
         .when()
             .post("http://localhost:2000")
         .then()
+            .log().ifValidationFails()
             .statusCode(200)
             .contentType("application/json")
             .body("fruits", hasSize(3))