Use a different ECC backend with a compatible serializer

This library has the ``SEC1`` encoder which is compatible
with the serialization of ECC keys/points used in the Go libp2p impl

setup.py

@@ -41,6 +41,7 @@ setuptools.setup(
         "lru-dict>=1.1.6",
         "protobuf==3.9.0",
         "coincurve>=10.0.0,<11.0.0",
+        "fastecdsa==1.7.4",
     ],
     extras_require=extras_require,
     packages=setuptools.find_packages(exclude=["tests", "tests.*"]),