enable `ES256K` for ECDSA signing scheme

[pohutukawa]

Ethereum, Bitcoin (and uPort) use the secp256k1 curve for their signature scheme. To allow for JWT (and other JOSE schemes) handling in uPort, the ES256K algorithm has been added.

Additionally, requirements-dev.txt contained a redundant entry ecdsa causing a pip install to fail due to it being already listed in the chained requirements.txt.

[codecov[bot]]

Codecov Report

Merging #113 into master will increase coverage by <.01%. The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #113      +/-   ##
==========================================
+ Coverage   96.55%   96.56%   +<.01%     
==========================================
  Files          14       14              
  Lines        1075     1076       +1     
==========================================
+ Hits         1038     1039       +1     
  Misses         37       37

Impacted Files	Coverage Δ
jose/backends/ecdsa_backend.py	98.66% <ø> (ø)	:arrow_up:
jose/backends/cryptography_backend.py	98.11% <ø> (ø)	:arrow_up:
jose/jwk.py	95.12% <ø> (ø)	:arrow_up:
jose/constants.py	100% <100%> (ø)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update e31416a...35fb5b8. Read the comment docs.

[pohutukawa]

Ping. Any insights on whether this might make it into python-jose or whether there's something I can do to make it suitable?

[wbobeirne]

I can confirm that this worked perfectly for my use-case (Decoding Blockstack JWTs, as they use ES256K encoding.) Would love to see this merged!

[pohutukawa]

I've just fixed up a minor merge conflict that's crept in due to this thing being a bit stale.