Hello all,

I have noticed that when I generate a presigned url for a file that will be uploaded to S3 that the Lambda function does not get triggered. It seems to only be happening for presigned url. I was able to successful have it trigger when I use the command line and upload a file through `aws s3 cp`. 

To recreate:
1: have any lambda function be added to an s3 bucket. My lambda configurations look as followed:
```
aws s3api --endpoint-url=http://localstack:4572 create-bucket --bucket mybucket;
aws s3api --endpoint-url=http://localstack:4572 create-bucket --bucket code;
aws s3 cp --endpoint-url=http://localstack:4572 --acl public-read /resources/example.zip s3://code/;
aws lambda create-function --endpoint-url=http://localstack:4574 --function-name MyLambdaFunction--runtime 'nodejs8.10' --handler 'index.handler' --role 'anyRole' --code S3Bucket=code,S3Key=example.zip,S3ObjectVersion=1.0.0;
```
Then add this lambda configuration to the bucket
```
{
    "LambdaFunctionConfigurations": [
        {
            "LambdaFunctionArn": "arn:aws:lambda:us-east-1:000000000000:function:MyLambdaFunction",
            "Events": [
                "s3:ObjectCreated:*"
            ]
        }
    ]
}
```
by running
```
aws s3api --endpoint-url=http://localstack:4572 put-bucket-notification-configuration --bucket 'mybucket' --notification-configuration file:///resources/notification.json;
```
2: Generate a presigned url for the bucket you added the lambda too

```
aws s3 presign --endpoint-url=http://localstack:4572 s3://mybucket/test.txt  --expires-in 300
```
3:
```
 curl --upload-file test.txt -v http://localstack:4572/mybucket/test.txt?AWSAccess
KeyId=dummyaccess&Expires=1571680684&Signature=TbCFh1rzkNYwNEooaQKcJPF4%2Fss%3D
```

Lambda does not seem to get triggered.

Any help or fixes?

Thank you so much for your time and help. Localstack has been a great tool!
import traceback
import pip as pip_mod
import shutil
try:
    import subprocess32 as subprocess
except Exception:
    import subprocess
import six
from localstack import constants, config
LOG = logging.getLogger(os.path.basename(__file__))
PLUGINS_LOADED = {}
IGNORED_LIB_MARKER = '#extended-lib'
BASIC_LIB_MARKER = '#basic-lib'
DO_CHMOD_DOCKER_SOCK = False
LOG_FORMAT = '%(asctime)s:%(levelname)s:%(name)s: %(message)s'
LOG_DATE_FORMAT = '%Y-%m-%dT%H:%M:%S'
PLUGIN_SCOPE_SERVICES = 'services'
PLUGIN_SCOPE_COMMANDS = 'commands'
API_DEPENDENCIES = {
    'dynamodbstreams': ['kinesis'],
    'lambda': ['logs'],
    'es': ['elasticsearch']
}
API_COMPOSITES = {
    'serverless': ['cloudformation', 'iam', 'sts', 'lambda', 'dynamodb', 'apigateway', 's3'],
    'cognito': ['cognito-idp', 'cognito-identity']
}
MAIN_CONTAINER_NAME = 'localstack_main'
mutex_popen = threading.Semaphore(1)
def bootstrap_installation():