Skip test failing due to tx endpoint metadata bug

REST::Neo4p 0.4003 can't parse the metadata for entities returned from Neo4j < 3.5 via the transaction endpoint (unless the Neo4j::Driver agent is used). This change prevents that bug from breaking the test suite.

To reproduce the bug (will trigger a "Can't call method on unblessed reference" error):

REST::Neo4p->begin_work;
(my $q = REST::Neo4p::Query->new('MATCH (n) RETURN n LIMIT 1'))->execute;
print $q->fetch->[0]->id;

Issues with the tx response format aren't new. The changelog for version 0.2220 included a fix for it, but the response format was updated in later Neo4j versions, forcing further changes. I believe the current iteration of the bug may have been introduced in 2077e4b.

t/041_v2_txns.t

@@ -31,6 +31,14 @@ diag "Test server unavailable (".$not_connected->message.") : tests skipped" if
 SKIP : {
   skip "Neo4j server version >= 2.0.0-M02 required, skipping...", $num_live_tests unless  REST::Neo4p->_check_version(2,0,0,2);
 
+  skip 'Returning entities via tx endpoint needs either Driver agent or Neo4j 3.5+', $num_live_tests
+    unless REST::Neo4p->_check_version(3,5,0,0)
+    || REST::Neo4p->agent->isa('REST::Neo4p::Agent::Neo4j::Driver');
+  # There is a known bug in _process_row/_response_entity in REST::Neo4p::Query
+  # that can prevent correct parsing of metadata for entities returned via the
+  # transaction endpoint. The metadata format varied between Neo4j versions.
+  # REST::Neo4p 0.3012-0.3030 worked correctly on some (not all) Neo4j versions.
+
 my $neo4p = 'REST::Neo4p';
 my ($n, $m);
 SKIP : {