Weld SE examples are missing slf4j impl dependency

When running 'mvn -Drun' on SE examples, it fails not being able to find org.slf4j.impl.StaticMarkerBinder class. When added org.slf4j:slf4j-simple dependency to pom.xml, the examples work fine.

[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.1.1:java (run) on project weld-se-hello-world: An exception occured while executing the Java class. null: InvocationTargetException: org/slf4j/impl/StaticMarkerBinder: org.slf4j.impl.StaticMarkerBinder -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.1.1:java (run) on project weld-se-hello-world: An exception occured while executing the Java class. null
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:203)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:140)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:316)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:153)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:451)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:188)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:134)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
Caused by: org.apache.maven.plugin.MojoExecutionException: An exception occured while executing the Java class. null
at org.codehaus.mojo.exec.ExecJavaMojo.execute(ExecJavaMojo.java:338)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:107)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:195)
... 19 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:283)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NoClassDefFoundError: org/slf4j/impl/StaticMarkerBinder
at org.slf4j.MarkerFactory.<clinit>(MarkerFactory.java:51)
at org.slf4j.cal10n.LocLogger.<clinit>(LocLogger.java:48)
at org.slf4j.cal10n.LocLoggerFactory.getLocLogger(LocLoggerFactory.java:59)
at org.jboss.weld.logging.LoggerFactory.getLogger(LoggerFactory.java:47)
at org.jboss.weld.bootstrap.WeldBootstrap.<clinit>(WeldBootstrap.java:124)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at java.lang.Class.newInstance0(Class.java:355)
at java.lang.Class.newInstance(Class.java:308)
at org.jboss.weld.environment.se.Weld.initialize(Weld.java:70)
at org.jboss.weld.environment.se.StartMain.go(StartMain.java:45)
at org.jboss.weld.environment.se.StartMain.main(StartMain.java:57)
... 6 more
Caused by: java.lang.ClassNotFoundException: org.slf4j.impl.StaticMarkerBinder
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
... 20 more