pre-build libraries for Julia packages and create default git config

Build and install native dependencies of bundled Julia packages in base image. Reduces build time and space requirement for Julia packages (Dockerfile v13).

Also generating a default git config for users on first login. 

Tests fail with the Ubuntu package, but pass when built from source and installed onto `/usr/local`. So will not use `coinor-libipopt-dev` and use the custom build steps instead now.