Make code python 3 compatible

[tyilo]

angr 8.0 has dropped python 2 support, so this should probably be updated accordingly.

[BlueSolarSystem]

i have tried to build this program using python Python 3.6.9 in virtul machine ubuntu 18 x64 , but still got some tiny problems on C code files like "error: invalid suffix "b" on integer constant" and "char buffer[8];\n char padding1['18b'];". However ,it does worked ,and output some elf files in "dist" directiry and some python files named like "scaffold00" .(This is my first time building this program , i change some code in it to fit python3)

[ZERO-A-ONE]

I set up a repository, there are Python3 and Ubuntu20.04 script