Change the format of the sha256.txt files

[pb8o]

As part of running a release, we publish sha256 checksum files like firecracker-v1.0.2-x86_64.tgz.sha256.txt

When trying to verify the checksum with standard tools we find that it fails:

cat firecracker-v1.0.2-x86_64.tgz | shasum -a 256 -c firecracker-v1.0.2-x86_64.tgz.sha256.txt
shasum: firecracker-v1.0.2-x86_64.tgz.sha256.txt: no properly formatted SHA checksum lines found

However the SHAs actually match, but the comparison needs to be done by eye or like so:

diff <(sha256sum firecracker-v1.0.2-aarch64.tgz |awk '{print $1}') firecracker-v1.0.2-aarch64.tgz.sha256.txt

... which is neither intuitive nor user-friendly.

We would like to gather some feedback from community if anybody depends on this behavior. Otherwise we will start producing normal sha256 checksum files in the future.

[pb8o]

Update: this is implemented since release 1.3.0