Fargate instances do not require memory and cpu descriptors. EC2 instances
do require descriptions. https://botocore.readthedocs.io/en/latest/reference/services/ecs.html#ECS.Client.describe_task_definition
Fargate requires that cpu and memory be defined at task definition level.
EC2 launch requires them to be defined at the container level.
Fargate requires the use of awsvpc for the networking_mode. Also updated,
the documentation regarding where and when memory/cpu needs to the assigned.
The task_definition variable for the awspvc configuration colided with
the ecs_service for the bridge network. This would cause the test to fail.
Add testing for fargate
Add examples for fargate and ec2
Enable awsvpc network mode for ECS services and tasks and
their underlying task definitions
Improve test suite to thoroughly test the changes
Use runme.sh technique to run old and new versions of botocore to
ensure that the modules work with older botocore and older network modes
and fail gracefully if awsvpc network mode is used with older botocore
