try to fix travis build

.travis.yml

@@ -1,7 +1,7 @@
 sudo: false
-#cache:
-#  directories:
-#    - $HOME/.m2
+cache:
+  directories:
+    - $HOME/.m2
 language: java
 jdk:
   - oraclejdk8

README.adoc

@@ -64,7 +64,7 @@ https://github.com/spring-cloud-samples/scripts[scripts demo
 repository] for specific instructions about the common cases of mongo,
 rabbit and redis.
 
-NOTE: migration to the Maven wrapper (`.mvnw`) is underway. If you
+NOTE: migration to the Maven wrapper (`./mvnw`) is underway. If you
 find a project that doesn't have it yet, raise an issue to get it
 added, and build with the command from `.travis.yml` (usually
 `mvn install -s .settings.xml`).

spring-cloud-starter-bus-amqp/pom.xml

@@ -6,7 +6,7 @@
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-bus-parent</artifactId>
 		<version>1.1.0.BUILD-SNAPSHOT</version>
-		<relativePath/>
+		<relativePath>..</relativePath>
 	</parent>
 	<artifactId>spring-cloud-starter-bus-amqp</artifactId>
 	<version>1.1.0.BUILD-SNAPSHOT</version>