Problem with the construction of the tag image string in `mcr_prepare_push`

Trying to push an image to AWS ECR using stevedore. Below is the error I get:

> d <- stevedore::docker_client()
Detected API version '1.41' is above max version '1.39'; downgrading
> d$image$push(name = "xxxxxxxx.dkr.ecr.us-east-1.amazonaws.com/testfromr")
The push refers to repository [xxxxxxxx.dkr.ecr.us-east-1.amazonaws.com/449283523352.dkr.ecr.us-east-1.amazonaws.com/testfromr]
An image does not exist locally with the tag: xxxxxxxx.dkr.ecr.us-east-1.amazonaws.com/449283523352.dkr.ecr.us-east-1.amazonaws.com/testfromr
Error: An image does not exist locally with the tag: xxxxxxxx.dkr.ecr.us-east-1.amazonaws.com/449283523352.dkr.ecr.us-east-1.amazonaws.com/testfromr

I traced it to here:

stevedore/R/docker_client_support.R

Line 836 in 5c281a8

name <- sprintf("%s/%s", name$registry, name$image)

Line 836 should read:

name <- sprintf("%s/%s", name$registry, name$name)

After which, it works:

> d <- stevedore::docker_client()
Detected API version '1.41' is above max version '1.39'; downgrading
> d$image$push(name = "xxxxxxxxx.dkr.ecr.us-east-1.amazonaws.com/testfromr")
The push refers to repository [xxxxxxxxx.dkr.ecr.us-east-1.amazonaws.com/testfromr]
Preparing 6ec33114c675
Preparing fce85200c8f4
...

@richfitz What would be a good way to handle this? Should I make a PR? Against the develop branch?

Thanks for the great package!

Thanks for the report - a PR would be great if you could. Just make it into master please