versions fix

[DennisDv24]

Im getting the following error while compiling the project:

could not compile dependency :ex_secp256k1, "mix compile" failed. Errors may have been logged above. You can recompile this dependency with "mix deps.compile ex_secp256k1 --force", update it with "mix deps.update ex_secp256k1" or clean it with "mix deps.clean ex_secp256k1"

After doing some tests on some project where I use this dependency, I concluded this happens because ex_web_ec_recover depends on version 0.5 of ex_abi, while ex_secp256k1 doesnt. So I updated the dependencies and did some minor integration fixes. All tests pass.

[DennisDv24]

I see some of you already got some work done on this (#26 #16)

[DennisDv24]

I forked this bc it looks dead