use instance_double in bosh_aws_cpi instance manager
use instance_double in bosh_aws_cpi instance manager

Signed-off-by: Dmitriy Kalinin <0638f5af938d97bf839390c6283ef9e40c331b8e@pivotallabs.com>

barthy1/bosh,barthy1/bosh,barthy1/bosh,barthy1/bosh