add missing httpcore dependency

fixes gh-37

pom.xml

@@ -184,6 +184,11 @@
 				<artifactId>httpclient</artifactId>
 				<version>${httpclient.version}</version>
 			</dependency>
+			<dependency>
+				<groupId>org.apache.httpcomponents</groupId>
+				<artifactId>httpcore</artifactId>
+				<version>${httpclient.version}</version>
+			</dependency>
 			<dependency>
 				<groupId>org.springframework.cloud</groupId>
 				<artifactId>spring-cloud-starter-zuul</artifactId>

spring-cloud-consul-core/pom.xml

@@ -43,6 +43,14 @@
 			<artifactId>gson</artifactId>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>org.apache.httpcomponents</groupId>
+			<artifactId>httpclient</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.httpcomponents</groupId>
+			<artifactId>httpcore</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>org.projectlombok</groupId>
 			<artifactId>lombok</artifactId>