Fix pointer types

[OverlordQ]

Removes the warnings, dont quote me on the properness of this fix, passes all tests. Fixes #16

[coveralls]

Coverage remained the same at 94.373% when pulling 5cc924b on OverlordQ:develop into f5e4552 on ludbb:master.

[coveralls]

Coverage remained the same at 94.373% when pulling 5cc924b on OverlordQ:develop into f5e4552 on ludbb:master.

[coveralls]

Coverage remained the same at 94.373% when pulling 5cc924b on OverlordQ:develop into f5e4552 on ludbb:master.

[coveralls]

Coverage remained the same at 94.373% when pulling 5cc924b on OverlordQ:develop into f5e4552 on ludbb:master.

[OverlordQ]

Failing test failed in Jenkins setup, not actual test-suite

[mcelrath]

Could we get this one merged? This warning message is driving me nuts. I've tested this patch and it works.

[ofek]

@ludbb Any thoughts?

[ofek]

This is fixed in my fork https://github.com/ofek/coincurve

[bartzy]

Will this PR be merged soon?

Thanks!

[ofek]

@bartzy Consider using https://github.com/ofek/coincurve

[ztane]

This seems a proper fix here. There are still other cases of char there that I think should be unsigned too.

[ofek]

@ztane Which?