GOSSIP-27 Missing ASF headers

Changing travis link in README
Removed maven section from readme
Adding NOTICE file in project
Adding DISCLAIMER file in codebase

src/test/java/org/apache/gossip/TenNodeThreeSeedTest.java

@@ -33,7 +33,6 @@ import org.apache.log4j.Logger;
 
 import org.apache.gossip.event.GossipListener;
 import org.apache.gossip.event.GossipState;
-import org.junit.After;
 import org.junit.jupiter.api.Test;
 
 @RunWith(JUnitPlatform.class)