Invoking a lambda that has been compiled by JDK 9+ with the following options causes `UnsupportedClassVersionError`. I think it's because of the fat jar compiled by JDK 8.

```
- LAMBDA_EXECUTOR=local
- LAMBDA_REMOTE_DOCKER=false
```

`
Exception in thread "main" java.lang.UnsupportedClassVersionError: ImageTransformer has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
`

The full log:
```
localstack_1               | 2020-02-26T09:29:49:WARNING:localstack.services.awslambda.lambda_executors: java  -cp /opt/code/localstack/localstack/infra/localstack-utils-fat.jar:/tmp/localstack/zipfile.ebe369ca/original_lambda_archive.zip:.:<classpath> cloud.localstack.LambdaExecutor ImageTransformer /tmp/localstack/lambda.event.b904f671.json
localstack_1               | 2020-02-26T09:29:50:WARNING:localstack.services.awslambda.lambda_api: Error executing Lambda function arn:aws:lambda:eu-west-1:000000000000:function:image-manager-lambda-local: Lambda process returned error status code: 1. Result: . Output:
localstack_1               | Exception in thread "main" java.lang.UnsupportedClassVersionError: ImageTransformer has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
localstack_1               | 	at java.lang.ClassLoader.defineClass1(Native Method)
localstack_1               | 	at java.lang.ClassLoader.defineClass(ClassLoader.java:757)
localstack_1               | 	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
localstack_1               | 	at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)
localstack_1               | 	at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
localstack_1               | 	at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
localstack_1               | 	at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
localstack_1               | 	at java.security.AccessController.doPrivileged(Native Method)
localstack_1               | 	at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
localstack_1               | 	at java.lang.ClassLoader.loadClass(ClassLoader.java:419)
localstack_1               | 	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
localstack_1               | 	at java.lang.ClassLoader.loadClass(ClassLoader.java:352)
localstack_1               | 	at java.lang.Class.forName0(Native Method)
localstack_1               | 	at java.lang.Class.forName(Class.java:264)
localstack_1               | 	at cloud.localstack.LambdaExecutor.getHandler(LambdaExecutor.java:150)
localstack_1               | 	at cloud.localstack.LambdaExecutor.main(LambdaExecutor.java:64) Traceback (most recent call last):
localstack_1               |   File "/opt/code/localstack/localstack/services/awslambda/lambda_api.py", line 379, in run_lambda
localstack_1               |     result, log_output = LAMBDA_EXECUTOR.execute(func_arn, func_details,
localstack_1               |   File "/opt/code/localstack/localstack/services/awslambda/lambda_executors.py", line 116, in execute
localstack_1               |     return do_execute()
localstack_1               |   File "/opt/code/localstack/localstack/services/awslambda/lambda_executors.py", line 101, in do_execute
localstack_1               |     raise e
localstack_1               |   File "/opt/code/localstack/localstack/services/awslambda/lambda_executors.py", line 90, in do_execute
localstack_1               |     result, log_output = self._execute(func_arn, func_details, event, context, version)
localstack_1               |   File "/opt/code/localstack/localstack/services/awslambda/lambda_executors.py", line 657, in _execute
localstack_1               |     process.run()
localstack_1               |   File "/usr/lib/python3.8/multiprocessing/process.py", line 108, in run
localstack_1               |     self._target(*self._args, **self._kwargs)
localstack_1               |   File "/opt/code/localstack/localstack/services/awslambda/lambda_executors.py", line 652, in do_execute
localstack_1               |     result = lambda_function(event, context)
localstack_1               |   File "/opt/code/localstack/localstack/services/awslambda/lambda_api.py", line 494, in execute
localstack_1               |     result, log_output = lambda_executors.EXECUTOR_LOCAL.execute_java_lambda(
localstack_1               |   File "/opt/code/localstack/localstack/services/awslambda/lambda_executors.py", line 675, in execute_java_lambda
localstack_1               |     result, log_output = self.run_lambda_executor(cmd)
localstack_1               |   File "/opt/code/localstack/localstack/services/awslambda/lambda_executors.py", line 153, in run_lambda_executor
localstack_1               |     raise Exception('Lambda process returned error status code: %s. Result: %s. Output:\n%s' %
localstack_1               | Exception: Lambda process returned error status code: 1. Result: . Output:
localstack_1               | Exception in thread "main" java.lang.UnsupportedClassVersionError: ImageTransformer has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
localstack_1               | 	at java.lang.ClassLoader.defineClass1(Native Method)
localstack_1               | 	at java.lang.ClassLoader.defineClass(ClassLoader.java:757)
localstack_1               | 	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
localstack_1               | 	at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)
localstack_1               | 	at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
localstack_1               | 	at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
localstack_1               | 	at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
localstack_1               | 	at java.security.AccessController.doPrivileged(Native Method)
localstack_1               | 	at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
localstack_1               | 	at java.lang.ClassLoader.loadClass(ClassLoader.java:419)
localstack_1               | 	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
localstack_1               | 	at java.lang.ClassLoader.loadClass(ClassLoader.java:352)
localstack_1               | 	at java.lang.Class.forName0(Native Method)
localstack_1               | 	at java.lang.Class.forName(Class.java:264)
localstack_1               | 	at cloud.localstack.LambdaExecutor.getHandler(LambdaExecutor.java:150)
localstack_1               | 	at cloud.localstack.LambdaExecutor.main(LambdaExecutor.java:64)
localstack_1               | 
```
Payload=b'{}', InvocationType='RequestResponse'
        )
        result_data = result['Payload'].read()
        result_data = json.loads(to_str(result_data))
        self.assertEqual(result['StatusCode'], 200)
        self.assertIsInstance(result_data, dict)
    def test_invocation_type_event(self):
        result = self.lambda_client.invoke(
            FunctionName=TEST_LAMBDA_NAME_PY,
            Payload=b'{}', InvocationType='Event')
        self.assertEqual(result['StatusCode'], 202)
    def test_invocation_type_dry_run(self):
        result = self.lambda_client.invoke(
            FunctionName=TEST_LAMBDA_NAME_PY, Payload=b'{}',
            InvocationType='DryRun')
        self.assertEqual(result['StatusCode'], 204)
    def test_lambda_environment(self):
        vars = {'Hello': 'World'}
        testutil.create_lambda_function(handler_file=TEST_LAMBDA_ENV, libs=TEST_LAMBDA_LIBS,
                                        func_name=TEST_LAMBDA_NAME_ENV, runtime=LAMBDA_RUNTIME_PYTHON27, envvars=vars)
        
        result = self.lambda_client.invoke(
            FunctionName=TEST_LAMBDA_NAME_ENV, Payload=b'{}')
        result_data = result['Payload']
        self.assertEqual(result['StatusCode'], 200)
        self.assertDictEqual(json.load(result_data), vars)
        
        result = self.lambda_client.get_function_configuration(
            FunctionName=TEST_LAMBDA_NAME_ENV)
        self.assertEqual(result['Environment'], {'Variables': vars})