tests: Ignore recent test binaries

Commits 6c6f312d and bd797fc1 added new tests (test-blockjob-txn
and test-timed-average, respectively), but did not mark them for
exclusion in .gitignore.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Message-id: 1447386423-13160-1-git-send-email-eblake@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

tests/.gitignore

@@ -9,6 +9,7 @@ check-qom-proplist
 rcutorture
 test-aio
 test-bitops
+test-blockjob-txn
 test-coroutine
 test-crypto-cipher
 test-crypto-hash
@@ -45,6 +46,7 @@ test-string-input-visitor
 test-string-output-visitor
 test-thread-pool
 test-throttle
+test-timed-average
 test-visitor-serialization
 test-vmstate
 test-write-threshold