Fixed compile error caused by missing import declaration

src/main/java/envoy/client/EnvoyClient.java

@@ -2,6 +2,7 @@ package envoy.client;
 
 import java.io.IOException;
 import java.time.Instant;
+import java.util.Arrays;
 import java.util.Properties;
 
 import javax.ws.rs.client.Client;