Remove Compiler Warnings

Fixes gh-346

spring-session/src/test/java/org/springframework/session/MapSessionTests.java

@@ -110,7 +110,7 @@ public class MapSessionTests {
 			return 0;
 		}
 
-		public Object getAttribute(String attributeName) {
+		public <T> T getAttribute(String attributeName) {
 			return null;
 		}
 

spring-session/src/test/java/org/springframework/session/data/gemfire/AbstractGemFireOperationsSessionRepositoryTest.java

@@ -159,8 +159,8 @@ public class AbstractGemFireOperationsSessionRepositoryTest {
 	@SuppressWarnings("unchecked")
 	public void gemfireOperationsSessionRepositoryIsProperlyConstructedAndInitialized() throws Exception {
 		ApplicationEventPublisher mockApplicationEventPublisher = mock(ApplicationEventPublisher.class);
-		AttributesMutator mockAttributesMutator = mock(AttributesMutator.class);
-		Region mockRegion = mock(Region.class);
+		AttributesMutator<Object,ExpiringSession> mockAttributesMutator = mock(AttributesMutator.class);
+		Region<Object,ExpiringSession> mockRegion = mock(Region.class);
 
 		when(mockRegion.getFullPath()).thenReturn("/Example");
 		when(mockRegion.getAttributesMutator()).thenReturn(mockAttributesMutator);

spring-session/src/test/java/org/springframework/session/data/redis/SessionMessageListenerTests.java

@@ -41,6 +41,7 @@ import org.springframework.session.events.SessionExpiredEvent;
  *
  */
 @RunWith(MockitoJUnitRunner.class)
+@SuppressWarnings("deprecation")
 public class SessionMessageListenerTests {
 	@Mock
 	ApplicationEventPublisher eventPublisher;

spring-session/src/test/java/org/springframework/session/data/redis/config/annotation/web/http/RedisHttpSessionConfigurationOverrideDefaultSerializerTests.java

@@ -55,6 +55,7 @@ public class RedisHttpSessionConfigurationOverrideDefaultSerializerTests {
 	@Configuration
 	static class Config {
 		@Bean
+		@SuppressWarnings("unchecked")
 		public RedisSerializer<Object> defaultRedisSerializer() {
 			return mock(RedisSerializer.class);
 		}

spring-session/src/test/java/org/springframework/session/data/redis/config/annotation/web/http/gh109/Gh109Tests.java

@@ -25,8 +25,6 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.data.redis.connection.RedisConnection;
 import org.springframework.data.redis.connection.RedisConnectionFactory;
 import org.springframework.data.redis.core.RedisOperations;
-import org.springframework.data.redis.core.RedisTemplate;
-import org.springframework.session.ExpiringSession;
 import org.springframework.session.data.redis.RedisOperationsSessionRepository;
 import org.springframework.session.data.redis.config.annotation.web.http.RedisHttpSessionConfiguration;
 import org.springframework.test.context.ContextConfiguration;