* Fixes bug where destructor was shutting down a thread pool executor that didn't yet exist (308)
Lambda Layer ARNs
python3.6, python3.7:
* ap-northeast-1: `arn:aws:lambda:ap-northeast-1:146318645305:layer:IOpipePython:9`
* ap-northeast-2: `arn:aws:lambda:ap-northeast-2:146318645305:layer:IOpipePython:9`
* ap-south-1: `arn:aws:lambda:ap-south-1:146318645305:layer:IOpipePython:9`
* ap-southeast-1: `arn:aws:lambda:ap-southeast-1:146318645305:layer:IOpipePython:9`
* ap-southeast-2: `arn:aws:lambda:ap-southeast-2:146318645305:layer:IOpipePython:9`
* ca-central-1: `arn:aws:lambda:ca-central-1:146318645305:layer:IOpipePython:9`
* eu-central-1: `arn:aws:lambda:eu-central-1:146318645305:layer:IOpipePython:9`
* eu-west-1: `arn:aws:lambda:eu-west-1:146318645305:layer:IOpipePython:9`
* eu-west-2: `arn:aws:lambda:eu-west-2:146318645305:layer:IOpipePython:9`
* eu-west-3: `arn:aws:lambda:eu-west-3:146318645305:layer:IOpipePython:9`
* us-east-1: `arn:aws:lambda:us-east-1:146318645305:layer:IOpipePython:10`
* us-east-2: `arn:aws:lambda:us-east-2:146318645305:layer:IOpipePython:9`
* us-west-1: `arn:aws:lambda:us-west-1:146318645305:layer:IOpipePython:9`
* us-west-2: `arn:aws:lambda:us-west-2:146318645305:layer:IOpipePython:9`
python2.7:
* ap-northeast-1: `arn:aws:lambda:ap-northeast-1:146318645305:layer:IOpipePython27:11`
* ap-northeast-2: `arn:aws:lambda:ap-northeast-2:146318645305:layer:IOpipePython27:9`
* ap-south-1: `arn:aws:lambda:ap-south-1:146318645305:layer:IOpipePython27:9`
* ap-southeast-1: `arn:aws:lambda:ap-southeast-1:146318645305:layer:IOpipePython27:9`
* ap-southeast-2: `arn:aws:lambda:ap-southeast-2:146318645305:layer:IOpipePython27:9`
* ca-central-1: `arn:aws:lambda:ca-central-1:146318645305:layer:IOpipePython27:9`
* eu-central-1: `arn:aws:lambda:eu-central-1:146318645305:layer:IOpipePython27:9`
* eu-west-1: `arn:aws:lambda:eu-west-1:146318645305:layer:IOpipePython27:9`
* eu-west-2: `arn:aws:lambda:eu-west-2:146318645305:layer:IOpipePython27:9`
* eu-west-3: `arn:aws:lambda:eu-west-3:146318645305:layer:IOpipePython27:9`
* us-east-1: `arn:aws:lambda:us-east-1:146318645305:layer:IOpipePython27:9`
* us-east-2: `arn:aws:lambda:us-east-2:146318645305:layer:IOpipePython27:9`
* us-west-1: `arn:aws:lambda:us-west-1:146318645305:layer:IOpipePython27:9`
* us-west-2: `arn:aws:lambda:us-west-2:146318645305:layer:IOpipePython27:9`