Fix spring unit tests.

Motivation
----------
afterPropertiesSet() needs to be called on the factory to actually
create the client so that it does not result in a NPE.

Change-Id: I483c045451f90ff3ed01d00db7e912e7d2484b64
Reviewed-on: http://review.couchbase.org/45554
Tested-by: Michael Nitschinger <michael.nitschinger@couchbase.com>
Reviewed-by: Simon Baslé <simon@couchbase.com>

src/test/java/net/spy/memcached/spring/MemcachedClientFactoryBeanTest.java

@@ -55,6 +55,8 @@ public void testGetObject() throws Exception {
     final Transcoder<Object> transcoder = new SerializingTranscoder();
     factory.setTranscoder(transcoder);
 
+    factory.afterPropertiesSet();
+
     final MemcachedClient memcachedClient =
         (MemcachedClient) factory.getObject();