"Dynamodb start" missing log4j/logger - exception

Console output:
```
>sls dynamodb start
Dynamodb Local Started, Visit: http://localhost:8000/shell

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/logging/log4j/Logger
at com.amazonaws.services.dynamodbv2.local.server.DynamoDBProxyServer.(DynamoDBProxyServer.java:36)
at com.amazonaws.services.dynamodbv2.local.main.ServerRunner.createServer(ServerRunner.java:123)
at com.amazonaws.services.dynamodbv2.local.main.ServerRunner.createServerFromCommandLineArgs(ServerRunner.java:119)
at com.amazonaws.services.dynamodbv2.local.main.ServerRunner.main(ServerRunner.java:70)
Caused by: java.lang.ClassNotFoundException: org.apache.logging.log4j.Logger
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 4 more
DynamoDB Local failed to start with code 1
```

Versions:

```
>sls --v
1.5.1

>java -version
java version "1.8.0_112"
Java(TM) SE Runtime Environment (build 1.8.0_112-b15)
Java HotSpot(TM) 64-Bit Server VM (build 25.112-b15, mixed mode)

>node -v
v7.2.0
```

Package.json:
```
"serverless-dynamodb-local": "^0.2.16",
"serverless-offline": "^3.8.3"
```

serverless.yaml
```
service: aws-nodejs-nexit

provider:
name: aws
runtime: nodejs4.3
functions:
hello:
handler: src/handler.hello
events:
- http:
path: hello
method: get
plugins:
- serverless-offline
- serverless-dynamodb-local

custom:
dynamodb:
start:
port: 8000
inMemory: true
migration: true
migration:
dir: ./offline/migrations
```

Reproduce the failure with `sls dynamodb start` using the versions and configuration in package.json and serverless.yaml. Inspect how the DynamoDB Local runtime is packaged and launched, then verify that the command starts without the missing `org/apache/logging/log4j/Logger` exception.

Written by the indexing model from the issue text.