Deprecates joda time usage

Fixes gh-612

spring-cloud-consul-discovery/src/main/java/org/springframework/cloud/consul/discovery/HeartbeatProperties.java

@@ -54,8 +54,11 @@ public class HeartbeatProperties {
 	@DecimalMax("0.9")
 	private double intervalRatio = 2.0 / 3.0;
 
-	// TODO: did heartbeatInterval need to be a field?
-
+	/**
+	 * @deprecated the joda time {@link Period} will be replaced with java8 duration.
+	 * @return the computed heartbeat interval
+	 */
+	@Deprecated
 	protected Period computeHearbeatInterval() {
 		// heartbeat rate at ratio * ttl, but no later than ttl -1s and, (under lesser
 		// priority), no sooner than 1s from now
@@ -68,6 +71,11 @@ public class HeartbeatProperties {
 		return heartbeatInterval;
 	}
 
+	@Deprecated
+	protected Period computeHeartbeatInterval() {
+		return computeHearbeatInterval();
+	}
+
 	public String getTtl() {
 		return this.ttlValue + this.ttlUnit;
 	}

spring-cloud-consul-discovery/src/main/java/org/springframework/cloud/consul/discovery/TtlScheduler.java

@@ -64,7 +64,7 @@ public class TtlScheduler {
 	public void add(String instanceId) {
 		ScheduledFuture task = this.scheduler.scheduleAtFixedRate(
 				new ConsulHeartbeatTask(instanceId), this.configuration
-						.computeHearbeatInterval().toStandardDuration().getMillis());
+						.computeHeartbeatInterval().toStandardDuration().getMillis());
 		ScheduledFuture previousTask = this.serviceHeartbeats.put(instanceId, task);
 		if (previousTask != null) {
 			previousTask.cancel(true);

spring-cloud-consul-discovery/src/test/java/org/springframework/cloud/consul/discovery/HeartbeatPropertiesTests.java

@@ -29,7 +29,7 @@ public class HeartbeatPropertiesTests {
 	@Test
 	public void computeHeartbeatIntervalWorks() {
 		HeartbeatProperties properties = new HeartbeatProperties();
-		Period period = properties.computeHearbeatInterval();
+		Period period = properties.computeHeartbeatInterval();
 
 		assertThat(period).isNotNull();
 		assertThat(period.getSeconds()).isEqualTo(20);
@@ -39,7 +39,7 @@ public class HeartbeatPropertiesTests {
 	public void computeShortHeartbeat() {
 		HeartbeatProperties properties = new HeartbeatProperties();
 		properties.setTtlValue(2);
-		Period period = properties.computeHearbeatInterval();
+		Period period = properties.computeHeartbeatInterval();
 
 		assertThat(period).isNotNull();
 		assertThat(period.getSeconds()).isEqualTo(1);