install.sh

[lsanchesdev]

i686-elf-tools-linux.zip being downloaded everytime the environment is build.
There is a whole structure implemented to avoid that:

1. The .zip file is downloaded to /docker-install, which is not a mapped volume
2. The .zip file is copied to /install, which is a mapped volume

The whole problem is at install.sh, there is an IF there that is not working. The original idea was to do:
if [ls /install | grep "i686-elf-tools-linux.zip"]; then
echo "OK";
else
wget -P /docker-install http://nimbleking.com/shiro/downloads/i686-elf-tools-linux.zip
fi

but for some reason the ls is not being recognized as a valid command when the script is called via CMD on Dockerfile.