Fix filename for dev requirements

[bth]

No description provided.

[CLAassistant]

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[bth]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
You have signed the CLA already but the status is still pending? Let us recheck it.

Sorry but when I go to https://cla-assistant.io/projecthamster/hamster-cli?pullRequest=179, I have this message:

There is no CLA to sign for projecthamster/hamster-cli
(could not find linked item for owner projecthamster and repo hamster-cli)