MINOR: add slf4jlog4j to streams example

Author: Guozhang Wang <wangguoz@gmail.com>

Reviewers: Ismael Juma <ismael@juma.me.uk>

Closes #1731 from guozhangwang/Kminor-log4j-streams-examples

(cherry picked from commit d903babb72)
Signed-off-by: Ismael Juma <ismael@juma.me.uk>

build.gradle

@@ -680,7 +680,12 @@ project(':streams') {
       exclude module: 'jline'
       exclude module: 'netty'
     }
-    compile libs.jacksonDatabind // this dependency should be removed after KIP-4
+
+    // zkclient has a hard log4j dependency, we set it here as well to avoid copying an older
+    // version to the binary package; the following two dependencies should be removed after KIP-4
+    // (along with the zkclient dependency)
+    compile libs.log4j
+    compile libs.jacksonDatabind
 
     testCompile project(':clients').sourceSets.test.output
     testCompile project(':core')
@@ -728,6 +733,7 @@ project(':streams:examples') {
   dependencies {
     compile project(':streams')
     compile project(':connect:json')  // this dependency should be removed after we unify data API
+    compile libs.slf4jlog4j           // this dependency should be removed after KIP-4
   }
 
   javadoc {

gradle/dependencies.gradle

@@ -31,6 +31,7 @@ versions += [
   jackson: "2.6.3",
   jetty: "9.2.15.v20160210",
   jersey: "2.22.2",
+  log4j: "1.2.17",
   jopt: "4.9",
   junit: "4.12",
   lz4: "1.3.0",
@@ -85,6 +86,7 @@ libs += [
   jettyServlets: "org.eclipse.jetty:jetty-servlets:$versions.jetty",
   jerseyContainerServlet: "org.glassfish.jersey.containers:jersey-container-servlet:$versions.jersey",
   junit: "junit:junit:$versions.junit",
+  log4j: "log4j:log4j:$versions.log4j",
   joptSimple: "net.sf.jopt-simple:jopt-simple:$versions.jopt",
   lz4: "net.jpountz.lz4:lz4:$versions.lz4",
   metrics: "com.yammer.metrics:metrics-core:$versions.metrics",