Add 'zlib-dev' package to container
== DETAILS
The retroarch codebase includes the code for a utility, elf2rpl
, which
converts the standard ELF binary format into the Wii U's native binary
format. This utility requires the zlib library in order to compile, which
was missing from the container.
== TESTING
- did local build of the Dockerfile
- ran salamander wiiu build and verified the
elf2rpl
compiled and ran successfully