Since version 0.14, the order of hashes does not seem to be deterministic.
Before 0.14, the hashes used to be lexicographically ordered.

I am guessing this was changed in #95

What is the reason for this?

We use hashin in electrum for deterministic builds.
The requirements files are generated by this script.
The freeze_packages.sh script is manually rerun to update dependencies (see e.g. spesmilo/electrum@ba4af29).
If the order of hashes for a given package is not canonical, then rerunning the script can result in changes for packages that have not actually been updated, making the diff considerably less readable.