Remove Makefile infrastructure
Shift directory structure
Fix doc build
Add new HashType RIPEMD160
Merge pull request #31 from yjerem/master

Add new HashType RIPEMD160
Derive thigs for error types
cargo update
Use BN_div instead of BN_mod

BN_mod is not available on all plateform and can be replaced by BN_div
with dv set as NULL.
Merge pull request #33 from isra17/master

Use BN_div instead of BN_mod
Add repr(C) to C structs
Merge pull request #34 from ebfe/repr_c

Add repr(C) to C structs
Switch to builtin language support on travis