Add spring boot configuration processor. Fixes #63 (#64)

spring-cloud-openfeign-core/pom.xml

@@ -168,6 +168,11 @@
 			<artifactId>spring-boot-autoconfigure-processor</artifactId>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-configuration-processor</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-test</artifactId>