Upgrade to feign 8.12.1

fixes gh-623

pom.xml

@@ -27,7 +27,7 @@
 		<main.basedir>${basedir}</main.basedir>
 		<archaius.version>0.6.5</archaius.version>
 		<eureka.version>1.3.4</eureka.version>
-		<feign.version>8.11.0</feign.version>
+		<feign.version>8.12.1</feign.version>
 		<hystrix.version>1.4.20</hystrix.version>
 		<ribbon.version>2.1.0</ribbon.version>
 		<servo.version>0.10.0</servo.version>

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/feign/SpringDecoderTests.java

@@ -115,6 +115,11 @@ public class SpringDecoderTests extends FeignClientFactoryBean {
 		assertEquals("header was wrong", "myval", header);
 	}
 
+	@Test(expected = RuntimeException.class)
+	public void test404() {
+		testClient().getNotFound();
+	}
+
 	@Data
 	@AllArgsConstructor
 	@NoArgsConstructor
@@ -122,21 +127,24 @@ public class SpringDecoderTests extends FeignClientFactoryBean {
 		private String message;
 	}
 
-	protected static interface TestClient {
+	protected interface TestClient {
 		@RequestMapping(method = RequestMethod.GET, value = "/helloresponse")
-		public ResponseEntity<Hello> getHelloResponse();
+		ResponseEntity<Hello> getHelloResponse();
 
 		@RequestMapping(method = RequestMethod.GET, value = "/hellovoid")
-		public ResponseEntity<Void> getHelloVoid();
+		ResponseEntity<Void> getHelloVoid();
 
 		@RequestMapping(method = RequestMethod.GET, value = "/hello")
-		public Hello getHello();
+		Hello getHello();
 
 		@RequestMapping(method = RequestMethod.GET, value = "/hellos")
-		public List<Hello> getHellos();
+		List<Hello> getHellos();
 
 		@RequestMapping(method = RequestMethod.GET, value = "/hellostrings")
-		public List<String> getHelloStrings();
+		List<String> getHelloStrings();
+
+		@RequestMapping(method = RequestMethod.GET, value = "/hellonotfound")
+		ResponseEntity<String> getNotFound();
 	}
 
 	@Configuration
@@ -175,6 +183,11 @@ public class SpringDecoderTests extends FeignClientFactoryBean {
 			return hellos;
 		}
 
+		@Override
+		public ResponseEntity<String> getNotFound() {
+			return ResponseEntity.status(HttpStatus.NOT_FOUND).body((String)null);
+		}
+
 		public static void main(String[] args) {
 			new SpringApplicationBuilder(Application.class).properties(
 					"spring.application.name=springdecodertest",