git & Docker modes

Signatures:

• git tag v0.2.1: 0x4e7c28741cab3a46d8b6be628294946c1a05c77d4b2ef659b9c4ab190830c822
• PyPI sdist stakesign-0.2.1.tar.gz: 0xd8286a7ea9f60da4a0e0e3cb28f413566cecccc960b6594c4889a9a54a6d36d3

Signing address: 0x83Cee747E4BCFF80938eA1056F925d1c24412f0b staked ≥1.00 ETH

v0.1.4

Adds --no-strict for compatibility with busybox sha256sum